Daily oral iron supplementation during pregnancy
Juan Pablo Peña-Rosas, Luz Maria De-Regil, Maria N Garcia-Casal, Therese Dowswell, Juan Pablo Peña-Rosas, Luz Maria De-Regil, Maria N Garcia-Casal, Therese Dowswell
Abstract
Background: Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it is thought to improve other maternal and birth outcomes.
Objectives: To assess the effects of daily oral iron supplements for pregnant women, either alone or in conjunction with folic acid, or with other vitamins and minerals as a public health intervention in antenatal care.
Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (10 January 2015). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) (26 February 2015) and contacted relevant organisations for the identification of ongoing and unpublished studies (26 February 2015) .
Selection criteria: Randomised or quasi-randomised trials evaluating the effects of oral preventive supplementation with daily iron, iron + folic acid or iron + other vitamins and minerals during pregnancy.
Data collection and analysis: We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. We used the GRADE approach to assess the quality of the evidence for primary outcomes.We anticipated high heterogeneity among trials and we pooled trial results using a random-effects model and were cautious in our interpretation of the pooled results: the random-effects model gives the average treatment effect.
Main results: We included 61 trials. Forty-four trials, involving 43,274 women, contributed data and compared the effects of daily oral supplements containing iron versus no iron or placebo.Preventive iron supplementation reduced maternal anaemia at term by 70% (risk ratio (RR) 0.30; 95% confidence interval (CI) 0.19 to 0.46, 14 trials, 2199 women, low quality evidence), iron-deficiency anaemia at term (RR 0.33; 95% CI 0.16 to 0.69, six trials, 1088 women), and iron deficiency at term by 57% (RR 0.43; 95% CI 0.27 to 0.66, seven trials, 1256 women, low quality evidence). There were no clear differences between groups for severe anaemia in the second or third trimester, or maternal infection during pregnancy (RR 0.22; 95% CI 0.01 to 3.20, nine trials, 2125 women, very low quality evidence; and, RR 1.21; 95% CI 0.33 to 4.46; one trial, 727 women, low quality evidence, respectively), or maternal mortality (RR 0.33; 95% CI 0.01 to 8.19, two trials, 12,560 women, very low quality evidence), or reporting of side effects (RR 1.29; 95% CI 0.83 to 2.02, 11 trials, 2423 women, very low quality evidence). Women receiving iron were on average more likely to have higher haemoglobin (Hb) concentrations at term and in the postpartum period, but were at increased risk of Hb concentrations greater than 130 g/L during pregnancy, and at term.Compared with controls, women taking iron supplements less frequently had low birthweight newborns (8.4% versus 10.3%, average RR 0.84; 95% CI 0.69 to 1.03, 11 trials, 17,613 women, low quality evidence), and preterm babies (RR 0.93; 95% CI 0.84 to 1.03, 13 trials, 19,286 women, moderate quality evidence). They appeared to also deliver slightly heavier babies (mean difference (MD) 23.75; 95% CI -3.02 to 50.51, 15 trials, 18,590 women, moderate quality evidence). None of these results were statistically significant. There were no clear differences between groups for neonatal death (RR 0.91; 95% CI 0.71 to 1.18, four trials, 16,603 infants, low quality evidence), or congenital anomalies (RR 0.88, 95% CI 0.58 to 1.33, four trials, 14,636 infants, low quality evidence).Twenty-three studies were conducted in countries that in 2011 had some malaria risk in parts of the country. In some of these countries/territories, malaria is present only in certain areas or up to a particular altitude. Only two of these studies reported malaria outcomes. There is no evidence that iron supplementation increases placental malaria. For some outcomes heterogeneity was higher than 50%.
Authors' conclusions: Supplementation reduces the risk of maternal anaemia and iron deficiency in pregnancy but the positive effect on other maternal and infant outcomes is less clear. Implementation of iron supplementation recommendations may produce heterogeneous results depending on the populations' background risk for low birthweight and anaemia, as well as the level of adherence to the intervention.
Conflict of interest statement
We certify that we have no affiliations with or involvement in any organisation or entity with a direct financial interest in the subject matter of the review (e.g. employment, consultancy, stock ownership, honoraria, expert testimony).
Juan Pablo Peña‐Rosas was author of an excluded study on iron and folic acid intermittent supplementation.
Luz Maria De‐Regil is full‐time staff member of the Micronutrient Initiative, an International Organization that delivers vitamin interventions to children, women of reproductive age and pregnant women, including iron and folic acid supplementation in eight countries in Africa and South East Asia.
Disclaimer: Juan Pablo Peña‐Rosas is currently a staff member of the World Health Organization. Maria Nieves Garcia‐Casal is a Consultant working for the World Health Organization. The authors alone are responsible for the views expressed in this publication and they do not necessarily represent the decisions, policy or views of the World Health Organization.
Therese Dowswell's institution (the University of Liverpool) has received an NIHR Cochrane Programme Grant and Therese is currently employed on this project. As part of her role, Therese helps volunteer review teams prepare Cochrane reviews. This review is not part of that portfolio of reviews. In the last 36 months Therese has received funding from the WHO to work on other Cochrane reviews. The Funders have no influence on the content or conclusions of the reviews Therese works on.
Figures
Study flow diagram.
'Risk of bias' graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.
'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study.
Funnel plot of comparison: 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), outcome: 1.1 Low birthweight (less than 2500 g) (ALL).
Funnel plot of comparison: 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), outcome: 1.6 Birthweight (g) (ALL).
Funnel plot of comparison: 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), outcome: 1.11 Preterm birth (less than 37 weeks of gestation) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 1 Low birthweight (less than 2500 g) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 2 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 3 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 4 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 5 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 6 Birthweight (g) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 7 Birthweight (g): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 8 Birthweight (g): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 9 Birthweight (g): SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 10 Birthweight (g): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 11 Preterm birth (less than 37 weeks of gestation) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 12 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 13 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 14 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 15 Preterm birth (less 37 weeks of gestation): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 16 Neonatal death (within 28 days after delivery) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 17 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 18 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 19 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 20 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 21 Congenital anomalies (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 22 Congenital anomalies: SUBGROUP ANALYSIS by gestational age at the start of supplementation).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 23 Congenital anomalies: SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 24 Congenital anomalies: SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 25 Congenital anomalies: SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 26 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 27 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by gestational age at the start of supplementation):.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 28 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by anaemia status at the start of supplementation).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 29 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by dose of iron).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 30 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by malarial status of setting).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 31 Maternal iron deficiency at term (as defined by as defined by trialists, based on any indicator of iron status at 37 weeks's gestation or more) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 32 Maternal iron deficiency at term (as defined by as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 33 Maternal iron deficiency at term (as defined by as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 34 Maternal iron deficiency at term (as defined by as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more): SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 35 Maternal iron deficiency at term (as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 36 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 37 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 38 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 39 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more): SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 40 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 41 Maternal death (death while pregnant or within 42 days of termination of pregnancy) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 42 Side effects (any reported throughout the intervention period) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 43 Side effects (any reported throughout the intervention period): SUBGROUP ANALYSIS by gestational age at the start of supplementation:.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 44 Side effects (any reported throughout the intervention period): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 45 Side effects (any reported throughout the intervention period): SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 46 Side effects (any reported throughout the intervention period): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 47 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 48 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 49 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 50 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 51 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 53 Infection during pregnancy (including urinary tract infections) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 54 Infection during pregnancy (including urinary tract infections): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 55 Infection during pregnancy (including urinary tract infections): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 56 Infection during pregnancy (including urinary tract infections): SUBGROUP ANALYSIS by dose of iron.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 57 Infection during pregnancy (including urinary tract infections): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 58 Very low birthweight (less than 1500 g) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 59 Very premature birth (less than 34 weeks' gestation) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 60 Infant Hb concentration within the first 6 months (in g/L counting the last reported measure after birth within this period) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 61 Infant serum ferritin concentration within first 6 months (in μg/L counting the last reported measure after birth within this period) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 62 Admission to special care unit (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 63 Maternal anaemia at or near term (Hb less than 110 g/L at 34 weeks' gestation or more) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 64 Maternal iron deficiency at or near term (as defined by as defined by trialists, based on any indicator of iron status at 34 weeks's gestation or more)) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 65 Maternal iron‐deficiency anaemia at or near term (Hb less than 110 g/L and at least one additional laboratory indicators at 34 weeks' gestation or more) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 66 Maternal Hb concentration at or near term (in g/L, at 34 weeks' gestation or more) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 67 Maternal Hb concentration within 6 wk postpartum (in g/L) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 68 Maternal high haemoglobin concentrations during second or third trimester (Hb more than 130 g/L) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 69 Maternal high haemoglobin concentrations at or near term (Hb more than 130 g/L at 34 weeks' gestation or more) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 70 Maternal severe anaemia at or near term (Hb less than 70 g/L at 34 weeks' gestation or more) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 71 Severe anaemia at postpartum (Hb less than 80 g/L) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 72 Moderate anaemia at postpartum (Hb more than 80 g/L and less than 110 g/L) (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 73 Puerperal infection (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 74 Antepartum haemorrhage (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 75 Postpartum haemorrhage (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 76 Transfusion provided (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 77 Diarrhoea (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 78 Constipation (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 79 Nausea (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 80 Heartburn (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 81 Vomiting (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 82 Maternal wellbeing/satisfaction (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 83 Placental abruption (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 84 Premature rupture of membranes (ALL).
Comparison 1 Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo), Outcome 85 Pre‐eclampsia (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 1 Low birthweight (less than 2500 g) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 2 Neonatal death (within 28 days after delivery) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 3 Preterm birth (less than 37 weeks of gestation) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 4 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by gestation at the start of supplementation.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 5 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 6 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by dose of iron.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 7 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by malarial status of settings.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 8 Birthweight (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 9 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by gestation at the start of supplementation.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 10 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 11 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by dose of iron.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 12 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by malarial status at the start of supplementation.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 13 Congenital anomalies (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 14 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 15 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by gestation at the start of supplementation.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 16 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 17 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by dose of iron.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 18 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 19 Maternal iron deficiency at term (as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 20 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 21 Maternal death (death while pregnant or within 42 days of termination of pregnancy) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 22 Side effects (any reported throughout the intervention period) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 23 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 24 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by gestation at the start of supplementation.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 25 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 26 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by dose of iron.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 27 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 29 Infection during pregnancy (including urinary tract infections) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 30 Very low birthweight (less than 1500 g) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 31 Very premature birth (less than 34 weeks' gestation) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 32 Admission to special care unit (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 33 Maternal anaemia at or near term (Hb less than 110 g/L at 34 weeks' gestation or more) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 34 Maternal iron deficiency at or near term (as defined by trialists, based on any indicator of iron status at 34 weeks' gestation or more) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 35 Maternal iron‐deficiency anaemia at or near term (Hb less than 110 g/L and at least one additional laboratory indicators at 34 weeks' gestation or more) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 36 Maternal Hb concentration at or near term (in g/L, at 34 weeks' gestation or more) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 37 Maternal Hb concentration within 6 wk postpartum (in g/L) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 38 Maternal high haemoglobin concentrations during second or third trimester (Hb more than 130 g/L) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 39 Maternal high haemoglobin concentrations at or near term (Hb more than 130 g/L at 34 weeks' gestation or more) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 40 Moderate anaemia at postpartum (Hb more than 80 g/L and less than 110 g/L) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 41 Maternal severe anaemia at or near term (Hb less than 70 g/L at 34 weeks' gestation or more ) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 42 Severe anaemia at postpartum (Hb less than 80 g/L) (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 43 Puerperal infection (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 44 Antepartum haemorrhage (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 46 Placental abruption (ALL).
Comparison 2 Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo), Outcome 47 Pre‐eclampsia (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 1 Low birthweight (less than 2500 g) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 2 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 3 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 4 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by dose of iron.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 5 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 6 Birthweight (g) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 7 Birthweight (g): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 8 Birthweight (g): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 9 Birthweight (g): SUBGROUP ANALYSIS by dose of iron.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 10 Birthweight (g): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 11 Preterm birth (less than 37 weeks of gestation) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 12 Preterm birth (less 37 weeks of gestation): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 13 Preterm birth (less 37 weeks of gestation): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 14 Preterm birth (less 37 weeks of gestation): SUBGROUP ANALYSIS by dose of iron.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 15 Preterm birth (less 37 weeks of gestation): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 17 Congenital anomalies (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 18 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 19 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 20 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks gestation or more): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 21 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by dose of iron.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 22 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 23 Maternal iron deficiency at term (as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 24 Maternal iron deficiency at term (as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 25 Maternal iron deficiency at term (as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 26 Maternal iron deficiency at term (as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more): SUBGROUP ANALYSIS by dose of iron.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 27 Maternal iron deficiency at term (as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 28 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 29 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 30 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 31 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more): SUBGROUP ANALYSIS by dose of iron.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 32 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 33 Maternal death (death while pregnant or within 42 days of termination of pregnancy) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 34 Side effects (any reported throughout the intervention period) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 35 Side effects (any reported throughout the intervention period): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 36 Side effects (any reported throughout the intervention period): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 37 Side effects (any reported throughout the intervention period): SUBGROUP ANALYSIS by dose of iron.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 38 Side effects (any reported throughout the intervention period): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 39 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 40 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 41 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by anaemia status age at the start of supplementation.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 42 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by dose of iron.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 43 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 46 Very low birthweight (less than 1500 g) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 47 Very premature birth (less than 34 weeks' gestation) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 48 Infant Hb concentration in the first 6 months (in g/L, counting the last reported measure after birth within this period) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 49 Infant serum ferritin concentration in the first 6 months (in μg/L, counting the last reported measure after birth within this period) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 50 Admission to special care unit (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 51 Maternal anaemia at or near term (Hb less than 110 g/L at 34 weeks' gestation or more) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 52 Maternal iron deficiency at or near term (as defined by trialists, based on any indicator of iron status at 34 weeks' gestation or more) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 53 Maternal iron‐deficiency anaemia at or near term (Hb less than 110 g/L and at least one additional laboratory indicators at 34 weeks' gestation or more) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 54 Maternal Hb concentration at or near term (in g/L, at 34 weeks' gestation or more) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 55 Maternal Hb concentration within 6 wk postpartum (in g/L) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 56 Maternal high haemoglobin concentrations during second or third trimester (Hb more than 130 g/L) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 57 Maternal high haemoglobin concentrations at or near term (Hb more than 130 g/L at 34 weeks' gestation or more) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 58 Moderate anaemia at postpartum (Hb more than 80 g/L and less than 110 g/L) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 59 Maternal severe anaemia at or near term (Hb less than 70 g/L at 34 weeks' gestation or more) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 60 Severe anaemia at postpartum (Hb less than 80 g/L) (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 61 Puerperal infection (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 62 Antepartum haemorrhage (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 63 Postpartum haemorrhage (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 64 Transfusion provided (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 65 Diarrhoea (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 66 Constipation (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 67 Nausea (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 68 Heartburn (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 69 Vomiting (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 70 Maternal wellbeing/satisfaction (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 71 Placental abruption (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 72 Premature rupture of membranes (ALL).
Comparison 3 Supplementation with iron alone versus no treatment/placebo, Outcome 73 Pre‐eclampsia (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 1 Low birthweight (less than 2500 g) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 2 Birthweight (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 3 Preterm birth (less than 37 weeks of gestation) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 4 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 5 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 6 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by dose of iron.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 7 Preterm birth (less than 37 weeks of gestation): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 8 Neonatal death (within 28 days after delivery) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 9 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by gestational age at start of supplementation.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 10 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by anaemia status at start of supplementation.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 11 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by dose of iron.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 12 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 13 Congenital anomalies (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 14 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 15 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 16 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 17 Maternal anaemia at term (Hb less than 110 g/Lat 37 weeks' gestation or more): SUBGROUP ANALYSIS by dose of iron.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 18 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 19 Maternal iron deficiency at term (as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 20 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 21 Maternal death (death while pregnant or within 42 days of termination of pregnancy) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 22 Side effects (any reported throughout the intervention period) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 23 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 25 Infection during pregnancy (including urinary tract infections) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 26 Very low birthweight (less than 1500 g) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 27 Very premature birth (less than 34 weeks' gestation) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 30 Admission to special care unit (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 31 Maternal anaemia at or near term (Hb less than 110 g/L at 34 weeks' gestation or more) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 32 Maternal iron deficiency at or near term (as defined by trialists, based on any indicator of iron status at 34 weeks' gestation or more) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 33 Maternal iron‐deficiency anaemia at or near term (Hb less than 110 g/L and at least one additional laboratory indicators at 34 weeks' gestation or more) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 34 Maternal Hb concentration at term or near term (in g/L, at 34 weeks' gestation or more) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 35 Maternal Hb concentration within 6 wk postpartum (g/L) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 36 Maternal high haemoglobin concentrations during second or third trimester (Hb more than 130 g/L) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 37 Maternal high haemoglobin concentrations at or near term (Hb more than 130 g/L at 34 weeks' gestation or more) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 38 Moderate anaemia at postpartum (Hb more than 80 g/L and less than 110 g/L) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 39 Maternal severe anaemia at term or near (Hb less than 70 g/L at 34 weeks' gestation or more) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 40 Severe anaemia at postpartum (Hb less than 80 g/L) (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 41 Puerperal infection (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 42 Antepartum haemorrhage (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 44 Placental abruption (ALL).
Comparison 4 Supplementation with iron+folic acid versus no treatment/placebo, Outcome 45 Pre‐eclampsia (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 1 Low birthweight (less than 2500 g) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 2 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 3 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 4 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by dose of iron.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 5 Low birthweight (less than 2500 g): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 6 Birthweight (g) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 7 Birthweight (g): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 8 Birthweight (g): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 9 Birthweight (g): SUBGROUP ANALYSIS by dose of iron.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 10 Birthweight (g): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 11 Preterm birth (less than 37 weeks of gestation) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 12 Preterm birth (less 37 weeks of gestation): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 13 Preterm birth (less 37 weeks of gestation): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 14 Preterm birth (less 37 weeks of gestation): SUBGROUP ANALYSIS by dose of iron.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 15 Preterm birth (less 37 weeks of gestation): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 16 Neonatal death (within 28 days after delivery) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 17 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 18 Neonatal death (within 28 days after delivery) : SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 19 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by dose of iron.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 20 Neonatal death (within 28 days after delivery): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 21 Congenital anomalies (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 22 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 23 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by gestational age at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 24 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more): SUBGROUP ANALYSIS by anaemia status at the start of supplementation.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 25 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more ): SUBGROUP ANALYSIS by dose of iron.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 26 Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more ): SUBGROUP ANALYSIS by malarial status of setting.
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 28 Maternal iron‐deficiency anaemia at term (Hb less than 110 g/L and at least one additional laboratory indicators at 37 weeks' gestation or more) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 30 Side effects (any reported throughout the intervention period) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 31 Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 33 Infection during pregnancy (including urinary tract infections) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 34 Very low birthweight (less than 1500 g) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 35 Very premature birth (less than 34 weeks' gestation) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 39 Maternal anaemia at or near term (Hb less than 110 g/L at 34 weeks' gestation or more) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 41 Maternal iron‐deficiency anaemia at or near term (Hb less than 110 g/L and at least one additional laboratory indicators at 34 weeks' gestation or more) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 42 Maternal Hb concentration at or near term (in g/L at 34 weeks' gestation or more) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 43 Maternal Hb concentration within 6 wk postpartum (in g/L) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 44 Maternal high haemoglobin concentrations during second or third trimester (Hb more than 130 g/L) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 45 Maternal high haemoglobin concentrations at or near term (Hb more than 130 g/L at 34 weeks' gestation or more) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 46 Moderate anaemia at postpartum (Hb more than 80 g/L and less than 110 g/L) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 47 Maternal severe anaemia at or near term (Hb less than 70 g/L at 34 weeks' gestation or more) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 48 Severe anaemia at postpartum (Hb less than 80 g/L) (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 49 Puerperal infection (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 50 Antepartum haemorrhage (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 51 Postpartum haemorrhage (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 52 Transfusion provided (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 53 Diarrhoea (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 54 Constipation (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 55 Nausea (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 56 Heartburn (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 59 Placental abruption (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 60 Premature rupture of membranes (ALL).
Comparison 5 Supplementation with iron+folic acid versus folic acid alone (without iron) supplementation, Outcome 61 Pre‐eclampsia (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 1 Low birthweight (less than 2500 g) (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 2 Birthweight (g) (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 3 Preterm birth (less than 37 weeks of gestation) (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 10 Side effects (any reported throughout the intervention period) (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 22 Maternal Hb concentration at or near term (in g/L at 34 weeks' gestation or more) (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 23 Maternal Hb concentration within 6 wk postpartum (in g/L) (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 33 Constipation (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 35 Heartburn (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 36 Vomiting (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 37 Diarrhoea (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 39 Placental abruption (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 40 Premature rupture of membranes (ALL).
Comparison 6 Supplementation with iron+other vitamins and minerals supplementation versus same other vitamins and minerals (without iron) supplementation, Outcome 41 Pre‐eclampsia (ALL).
Source: PubMed