Effect of Folic Acid Supplementation in Pregnant Women Having Thalassaemia Trait

November 27, 2023 updated by: The University of Hong Kong

A Randomized Controlled Trial to Study the Effect of Folic Acid Supplementation in Pregnant Women Having Thalassaemia Trait

Folic acid supplementation has been recommended for prevention of neural tube defects in pregnancy when taken periconceptionally up to 12 weeks of gestation. A daily dose of 0.4mg has been endorsed by World Health Organisation to achieve a Red blood cell (RBC) folate level of 906nmol/L (400ng/mL) for reduction of neural tube defect. Hong Kong has no policy on food fortification. Research data conducted in countries with food fortification may not be applicable. It is therefore essential to study the baseline folate status in pregnant women locally.

For pregnant women with thalassaemia, they are believed to have a higher risk of folate deficiency because of an increased rate of erythropoiesis and chronic haemolysis. However, information on folate level of thalassaemia trait in pregnancy is scanty. Unmetabolized folic acid has been detected in maternal and fetal blood when daily dosage greater than 0.8-1mg was taken. In term of the dosage and duration of folic acid supplementation after 12 weeks of gestation, the practice varies widely among public hospitals and Maternity & Child Health Care centres. It is therefore essential to study the optimal dosage of folic acid supplementation in women with thalassaemia.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Folic acid supplementation is well established for its role in prevention of neural tube defects (NTD) when taken periconceptionally up to 12 weeks of gestation. The naturally occurring form, folate, is a water soluble B vitamin (B9) that is mostly present in dark green leafy vegetables and legumes. However, it is only 50% bioavailable. Folic acid, on the contrary, as a synthetic form of folate is almost completely bioavailable especially when administered in an empty stomach. It has been endorsed by World Health Organisation that RBC folate cutoff of 906 nmol/L (400ng/mL) is required for reduction of NTD. This level is only achievable by taking Folic acid supplementation of 0.4mg/day. Women at higher risk of having recurrent NTD is recommended to take higher dose at 4mg/day.

Patients with thalassaemia have an increased rate of erythropoiesis and chronic haemolysis. They are believed to have a higher rate of folate turnover and consequentially higher risk of folate deficiency. Guideline from Royal College of Obstetricians and Gynaecologists recommends daily intake of 5mg folic acid preconceptionally to prevent NTD. But, it does not specify whether this dosage is applicable to all types and degrees of thalassaemias and research data on the optimal dosage is lacking.

In addition to prevention of NTD, the supplementation of folic acid is also recommended for pregnant thalassaemia women for prevention of antenatal anaemia. In a retrospective study of Chinese population reported in 1989, women with beta-thalassaemia minor taking additional 5mg folic acid had higher pre-delivery haemoglobin concentration of 10.1 g/dL compared to haemoglobin level of 9.7 g/dL in the group taking Obimin (a pregnancy supplement containing 0.25mg folic acid and 90 mg ferrous fumarate). However, there was no further randomised controlled trial to validate this observation. Though a higher folic acid supplementation was believed to be beneficial in prevention of antenatal anaemia, unmetabolized folic acid were detected in maternal and fetal blood when daily dosage greater than 0.8-1mg was taken. Moreover, a higher rate of urinary excretion of folic acid was also observed in pregnant women receiving higher dosage of folic acid supplementation.

In non-pregnant beta thalassaemia major patients, folic acid supplementation at 1 mg daily was advised as cessation of which could lead to a significant reduction in serum folate. This has been counter-proposed by the observation of normal to high serum folate levels in transfusion dependent thalassaemia receiving optimal transfusion. Indeed, folic acid supplementation should be considered for non-transfusion dependent thalassaemia as excessive erythropoiesis is required to maintain satisfactory haemoglobin.

Folate level drops during pregnancy to puerperal period. Information on folate level of thalassaemia trait in pregnancy is scanty. In a paper published in 1985, no difference in serum folate was found between normal women and women with thalassaemia trait, and hence usual supplementation was suggested.

Hong Kong has no policy on food fortification. Research data conducted in countries with food fortification may not be applicable. The folate status may have been changed in last few decades because of better general nutritional status and public knowledge of preconception folic acid supplementation. The preparation of 5mg folic acid is available in all public hospitals and preparation of 0.5mg folic acid is recently introduced. As such, the 5mg folic acid prescription is traditionally adopted and this can be a result of its availability. However, the practice varies widely among public hospitals and Maternity & Child Health Care centres. There is no standardised guideline on the dosage and indications of folic acid supplementation for pregnant thalassaemic women. More importantly, no recent data on the baseline folate status in pregnant women with thalassaemia is available locally.

Patient blood management in Obstetrics has been advocated with an aim to minimize blood loss by maintaining haemoglobin levels, reduce blood transfusion and optimize patient outcome. Identification and treatment of maternal anaemia is one of the three main pillars to achieve it. Even though thalassaemia can be considered as a risk factor for NTD, it remains controversial as to how much folic acid supplementation is adequate for pregnant women with thalassaemia trait in prevention of maternal anaemia which is a key element in maternity care.

Study Type

Interventional

Enrollment (Estimated)

270

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Pui Wah Hui, MD
  • Phone Number: 852-22553402
  • Email: apwhui@hku.hk

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Singleton pregnancy
  • Alpha thalassaemia trait
  • Beta thalassaemia trait

Exclusion Criteria:

  • Women taking over 0.6mg folic acid daily for 3 months or more prior to and during pregnancy
  • Gestational age > 16 weeks at first antenatal visit
  • Women age =< 18 years old
  • Booking BMI =< 18 or >= 35
  • Serum ferritin level < 30ug/L or 68 pmol/L
  • Concomitant alpha and beta thalassaemia
  • Hb H disease
  • Beta thalassaemia major
  • Beta thalassaemia intermediate
  • Thalassaemia other than alpha or beta type
  • Women on long term medications
  • Women with risk factors for NTD
  • Women with known epilepsy
  • Women with bariatric surgery or malabsorption diseases
  • Women with known MTHFR polymorphism
  • Vegetarian

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Folic acid 5mg
Dietary supplement: Folic acid
women will be randomised into one of the three groups. Group A - Folic acid 5mg/day Group B - Folic acid 0.5mg/day Group C - Materna one tablet/day (a pregnancy supplement containing 0.6mg folic acid)
Active Comparator: Folic acid 0.5mg
Dietary supplement: Folic acid
women will be randomised into one of the three groups. Group A - Folic acid 5mg/day Group B - Folic acid 0.5mg/day Group C - Materna one tablet/day (a pregnancy supplement containing 0.6mg folic acid)
Active Comparator: Materna
Dietary supplement: Materna
Materna

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Haemoglobin level
Time Frame: Change in level throughout the pregnancy, up to 42 weeks
Change in level throughout the pregnancy, up to 42 weeks
Maternal RBC folate concentration
Time Frame: Change in level throughout the pregnancy, up to 42 weeks
Change in level throughout the pregnancy, up to 42 weeks
Maternal serum folate concentration
Time Frame: Change in level throughout the pregnancy, up to 42 weeks
Change in level throughout the pregnancy, up to 42 weeks
Cord blood RBC
Time Frame: Upon birth
Upon birth
Cord blood serum folate concentration
Time Frame: Upon birth
Upon birth

Secondary Outcome Measures

Outcome Measure
Time Frame
Ferritin level
Time Frame: Change in level throughout the pregnancy, up to 42 weeks
Change in level throughout the pregnancy, up to 42 weeks
Maternal Vitamin B12
Time Frame: Maternal Vitamin B12 at first antenatal visit
Maternal Vitamin B12 at first antenatal visit
Cord blood vitamin B12
Time Frame: Cord blood vitamin B12 upon birth
Cord blood vitamin B12 upon birth

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

The University of Hong Kong

Collaborators

Queen Mary Hospital, Hong Kong

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 1, 2024

Primary Completion (Estimated)

July 31, 2025

Study Completion (Estimated)

July 31, 2026

Study Registration Dates

First Submitted

March 5, 2020

First Submitted That Met QC Criteria

March 12, 2020

First Posted (Actual)

March 17, 2020

Study Record Updates

Last Update Posted (Actual)

November 29, 2023

Last Update Submitted That Met QC Criteria

November 27, 2023

Last Verified

November 1, 2023

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UW 20-084

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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