When to INDuce for OverWeight? (WINDOW) (WINDOW)

When to INDuce for OverWeight? - a Randomised Controlled Trial (WINDOW)

The rate of overweight and obese women becoming pregnant is increasing. Obesity in pregnancy along with delivery by cesarean section in obese women is associated with several complications as compared to normal weight women. The longer the woman is pregnant, the longer she is at risk. In an otherwise low-risk pregnant woman at term, it is an ongoing clinical dilemma, whether the benefits of elective induction of labor and termination of the pregnancy will outweigh the potential harms from concomitant induction and delivery process. The proposed study is a randomized controlled study of elective induction versus expectant management in obese women. The study will be carried out as a national multicenter study with inclusion of 1900 participants from Danish delivery wards. The null hypothesis is that the caesarean section rate is similar with elective induction of labor at 39 weeks of gestation, compared with expectant management among pregnant women with pre- or early pregnancy BMI≥30.

Study Overview

• Status: Recruiting
• Conditions: Obesity; Pregnancy; Parturition
• Intervention / Treatment: Procedure: Elective induction of labor at 39 gestational weeks and 0 to 3 days

Detailed Description

Background The World Health Organization (WHO) defines overweight as a body mass index (BMI) of ≥25 kg/m2 and obesity as a BMI of ≥30 kg/m2. Overweight and obesity are rising dramatically worldwide. In fertile women, the prevalence of obesity is one third in the United States, 20% in the United Kingdom, and 12-13% in Denmark. The association between obesity in pregnancy and the risk of gestational complications increases with increasing BMI. Among other complications, obesity in pregnancy is associated with increased risk of caesarean delivery. Delivery by caesarean section further adds significant risks of wound infection or other infectious morbidity in obese women as compared to normal weight women. The longer the woman is pregnant, the longer the risk of pregnancy complications remains. In an otherwise low-risk pregnant woman at term, it is an on-going clinical dilemma, whether the benefits of elective induction of labor (eIOL) and termination of the pregnancy will outweigh the potential harms from the concomitant induction and delivery process. Regarding delivery complications, based on data from historical cohorts, eIOL has traditionally been associated with an increased risk of caesarean section and instrumental delivery. Therefore, expectant management has been the preferred clinical option. This interpretation has now been challenged by a randomized trial (ARRIVE) with >6000 low-risk pregnant women where eIOL at 39 weeks of gestation was associated with lower caesarean delivery rates. There are no randomized studies in obese women, but two larger observational studies did find lower odds of caesarean delivery in obese women with eIOL as compared to awaiting labor onset. Hence, a randomized trial that would compare caesarean delivery among obese women whose labor is induced with those expectantly managed is warranted. The proposed study will provide new and important knowledge into the area of induction of labor among overweight and obese women with potential great international impact for the future raising number of pregnant women in this subgroup.

With this trial, the investigators aim to compare the risk of caesarean section in obese (BMI ≥ 30 kg/m2), but otherwise low-risk women with eIOL as compared to expectant management.

Materials and methods

The study is a multicenter randomized controlled trial with an allocation ratio of 1:1 in the two following arms:

• Intervention arm/elective induction of labor in pregnancy at 39 gestational week and 0 to 3 days: Induction is performed according to local policy for induction of labor.

• Comparison arm/expectant management: Waiting for spontaneous onset of labor unless a situation develops necessitating either induction of labor or caesarean section.

  1900 low-risk pregnant women with a pre- or early pregnancy BMI ≥ 30 carrying a singleton pregnancy will be recruited from the Danish delivery wards. In each trial site, a physician investigator will be responsible for the enrolment, the electronically randomization, and data collection.

The primary endpoint is the caesarean section rate. Among others there will be secondary endpoints on instrumental delivery, onset of labor, methods of induction, perinatal and postpartum complications both maternal and neonatal along with data on women's experience on birth measured by a questionnaire survey four to six weeks post-partum.

Ethics The study will be conducted in accordance with the ethical principles outlined in the latest version of the 'Declaration of Helsinki' and the 'Guideline for Good Clinical Practice' related to experiments on humans. The Central Denmark Region Committee on Biomedical Research Ethics, and The Danish Health Authorities have approved the study.

Perspectives In perspective, more than 39% of the world's population is overweight and 13% are obese by the WHO classification. Pregnant overweight women are at increased risk of pregnancy and delivery complications, and there is a need to improve maternity care for this subgroup of women. The results of this trial have the potential to generate important knowledge for the improvement of delivery in obese women and they will add key information to an on-going discussion of the effects of labor induction before term. Any possible harm or disadvantage to the individual study participant is outweighed by the possible benefit to the increasing number of obese women who will be pregnant in the future.

• Study Type: Interventional
• Enrollment (Estimated): 1900
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Lise Q Krogh, MD; Phone Number: 0045 51242102; Email: lise.qvirin.krogh@clin.au.dk

Study Locations

• Denmark
  • Aarhus, Denmark
    • Recruiting
    • Aarhus University Hospital
    • Contact: Lise Q Krogh, MD
  • Herlev, Denmark
    • Recruiting
    • Herlev Hospital
    • Contact: Lene Huusom, MD, PhD
  • Herning, Denmark
    • Recruiting
    • Gødstrup Regional Hospital
    • Contact: Iben Sundtoft, MD, PhD
  • Hillerød, Denmark
    • Recruiting
    • North Zealand's Hospital
    • Contact: Hanne B Westergaard, MD, PhD
  • Hvidovre, Denmark
    • Recruiting
    • Hvidovre Hospital
    • Contact: Lone Krebs, MD, PhD
  • Kolding, Denmark
    • Recruiting
    • Kolding Hospital
    • Contact: Anne Cathrine H Munk, MD
  • København, Denmark
    • Recruiting
    • Rigshospitalet Juliane Marie Centre
    • Contact: Kristina Renault, MD, DMSc
  • Nykøbing Falster, Denmark
    • Recruiting
    • Nykøbing Falster Hospital
    • Contact: Jeannet Lauenborg, MD, PhD
  • Odense, Denmark
    • Recruiting
    • Odense University Hospital
    • Contact: Christina Vinter, MD, PhD
  • Randers, Denmark
    • Recruiting
    • Randers Regional Hospital
    • Contact: Pinar Bor, MD, PhD
  • Roskilde, Denmark
    • Recruiting
    • Zealand University Hospital
    • Contact: Nana Wiberg, MD
  • Viborg, Denmark
    • Recruiting
    • Viborg Hospital
    • Contact: Lise Clausen, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Pregnant women with pre- or early pregnancy BMI ≥ 30 kg/m2

Exclusion Criteria:

• Legal or ethical considerations: maternal age <18 years, language difficulties requiring an interpreter or translator
• Multiple pregnancy
• Previous caesarean section
• Uncertain gestational age, defined as gestational age determined by other measurements than the Crown-Rump length (CRL) Measurement
• Planned elective caesarean section at time of randomisation
• Fetal contraindications to IOL at time of randomisation: e.g. non-cephalic presentation, or other fetal conditions contraindicating vaginal delivery
• Fetal contraindications to expectant management at time of randomisation
• Maternal contraindications to IOL at time of randomisation: e.g. placenta previa/accreta, vasa previa
• Maternal contraindications to expectant management at time of randomisation: e.g. maternal medical conditions, ultrasonically diagnosed oligohydramnios (DVP< 2 cm), signs of labour including pre-labour rupture of membranes (PROM)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Elective induction of labour; Elective induction of labour at 39 gestational weeks and 0 to 3 days.	Procedure: Elective induction of labor at 39 gestational weeks and 0 to 3 days; Elective induction of labor (eIOL) according to local policies; Other Names: eIOL
No Intervention: Expectant management; Awaiting spontaneous labor.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Caesarean section	number (no.)	At delivery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mode of delivery if not by caesarean	Vaginal delivery - no.; Vaginal assisted delivery - no.	At delivery
Mode of delivery	Caesarean section - percent; Vaginal delivery - percent; Vaginal assisted delivery - percent	At delivery
Vaginal assisted delivery	Forceps - no.; Ventouse - no.	At delivery
Indication for caesarean section (more than one indication is possible)	Labour dystocia - no.; Fetal distress - no.; Maternal request - no.; Suspected macrosomia - no.; Non-cephalic presentation - no.; Extensive vaginal bleeding - no.; Suspected uterine rupture - no.; Maternal or fetal complication/condition (free text) - no.; Other indication for caesarean section (free text) - no.	At delivery
Indication for vaginal assisted delivery (more than one is possible)	Labour dystocia - no.; Fetal distress - no.; Maternal request - no.; Other indication for assisted vaginal delivery (free text) - no.	At delivery
Use of epidural	no.	At delivery
Damage to internal organs (bladder, bowel or ureters)	no.	At delivery to 30 days postpartum
Uterine scar dehiscense or rupture	no.	At delivery
Complications	Minor shoulder dystocia defined as the need for McRobert's maneuver - no.; Major shoulder dystocia defined as the need for procedures other than McRobert's maneuver - no.; Clinical suspicion of abruption of the placenta leading to an intervention in labour - no.; Cord prolapse - no.; Maternal fever defined as temperature >38,2 / >38,0 degrees celsius with / without epidural - no.; Perineal 3rd degree laceration - no.; Perineal 4th degree laceration - no.; Episiotomy - no.	At delivery
Postpartum haemorrhage	Blood loss >500ml - no.; Blood loss >1000ml - no.; Blood transfusion - no. Time Frame [0-2 days postpartum]	0-2 hours postpartum
Hysterectomy	no.	At delivery to 30 days postpartum
Postpartum morbidity	Puerperal infection treated in hospital - no.; Other severe postpartum conditions treated in hospital (free text) - no.	0-30 days postpartum
Maternal admission to Intensive Care Unit	no.	Enrollment to 30 days postpartum
Maternal cardiopulmonary arrest	no.	Enrollment to 30 days postpartum
Maternal death	no.	Enrollment to 30 days postpartum
Primary neonatal composite including any of the following;	Perinatal death (stillbirth and neonatal); The need for respiratory support if admitted to a neonatal department (intubation and mechanical ventilation, oxygen, continuous positive airway pressure (CPAP), or high-flow nasal cannula (HNFC)). Time Frame [within 72 hours after birth]; Apgar score < 4 at 5 minutes; Hypoxic-ischemic encephalopathy (defined as the need for therapeutic hypothermia); Seizures; Infection (defined as antibiotic treatment continuously for 7 days minimum); Meconium aspiration syndrome; Birth trauma (bone fracture, Duchenne-Erbs palsy, or retinal hemorrhage); Intracranial or subgaleal hemorrhage; Hypotension requiring vasopressor support	Enrollment to 28 days of life
Components of the primary neonatal composite will additionally be reported separately	Perinatal death (stillbirth and neonatal) - no.; The need for respiratory support if admitted to a neonatal department (intubation and mechanical ventilation, oxygen, continuous positive airway pressure (CPAP), or high-flow nasal cannula (HNFC)). Time Frame [within 72 hours after birth] - no.; Apgar score < 4 at 5 minutes - no.; Hypoxic-ischemic encephalopathy (defined as the need for therapeutic hypothermia) - no.; Seizures - no.; Infection (defined as antibiotic treatment continuously for 7 days minimum) - no.; Meconium aspiration syndrome - no.; Birth trauma (bone fracture, Duchenne-Erbs palsy, or retinal hemorrhage) - no.; Intracranial or subgaleal hemorrhage - no.; Hypotension requiring vasopressor support - no.	Enrollment to 28 days of life
Neonatal trauma composite including any of the following;	Birth trauma (bone fracture, Duchenne-Erbs palsy, or retinal hemorrhage); Intracranial or subgaleal hemorrhage	At delivery to 28 days of life
Neonatal asphyxia composite including any of the following;	Apgar score < 4 at 5 minutes; Umbilical cord pH-value < 7.0 (allow missing data); Umbilical cord standard base excess (sBE) < -15.0 mmol/l (allow missing data); Seizures; Hypoxic-ischemic encephalopathy (defined as the need for therapeutic hypothermia)	At delivery to 28 days of life
Apgar score at 5 minutes	Apgar score <4 - no.; Apgar score of 4-7 - no.	5 minutes of life
Umbilical cord arterial and venous blood sample (allow missing data)	pH-value < 7.0 - no.; sBE < -15.0 mmol/l - no.	0-30 minutes of life
Neonatal admission	no.	0-72 hours of life
Respiratory support during neonatal admission	CPAP (y/n) - no.; HNFC (y/n) - no.; Oxygen supplement treatment (y/n) - no.; Ventilator treatment (y/n) - no.	0-28 days of life
Other treatment during neonatal admission	Therapeutic hypothermia (y/n) - no.; Vasopressor support (y/n) - no.; Antibiotic treatment continuously for 7 days minimum (y/n) - no.	0-28 days of life

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neonatal characteristics 1	Female sex - no.; Birth weight > 4500 grams (y/n) - no.	At delivery
Neonatal characteristics 2	- Mean birth weight - grams	At delivery
Maternal experience on birth	Childbirth Experience Questionnaire Scoring range is 1 to 4 where higher ratings reflect more positive experiences	4-6 weeks postpartum
Maternal postnatal depression	Major Depression Inventory (MDI); Edinburgh Postnatal Depression Score Scoring range is 1 to 4 where higher ratings reflect more positive experiences	4-6 weeks postpartum

Collaborators and Investigators

• Sponsor: University of Aarhus
• Collaborators: Odense University Hospital; Aarhus University Hospital; Hvidovre University Hospital; Herning Hospital; Herlev Hospital; Nykøbing Falster County Hospital; Kolding Sygehus; Randers Regional Hospital; Central Jutland Regional Hospital; Rigshospitalet Juliane Marie Centret; North Zealand's Hospital; Zealand University Hospital - Roskilde
• Investigators: Principal Investigator: Lise Q Krogh, MD, Aarhus University Hospital; Study Chair: Julie Glavind, MD, PhD, Aarhus University Hospital; Study Chair: Sidsel Boie, MD, PhD, Randers Regional Hospital; Study Chair: Jens Fuglsang, MD, PhD, Aarhus University Hospital; Study Chair: Tine B Henriksen, MD, PhD, Aarhus University Hospital; Study Chair: Jim Thornton, MD, PhD, Nottingham University; Study Chair: Katja A Taastrøm, Midwife, MSc, Aarhus University Hospital; Study Chair: Anne Cathrine M Kjeldsen, Midwife, MSc, Aarhus University Hospital

Publications and helpful links

General Publications

• Krogh LQ, Boie S, Henriksen TB, Thornton J, Fuglsang J, Glavind J. Induction of labour at 39 weeks versus expectant management in low-risk obese women: study protocol for a randomised controlled study. BMJ Open. 2022 Apr 25;12(4):e057688. doi: 10.1136/bmjopen-2021-057688.

Study record dates

Study Major Dates

• Study Start (Actual): October 19, 2020
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: October 12, 2020
• First Submitted That Met QC Criteria: October 20, 2020
• First Posted (Actual): October 27, 2020

Study Record Updates

• Last Update Posted (Actual): October 4, 2023
• Last Update Submitted That Met QC Criteria: October 1, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Keywords: Cesarean section; Induction of labor; Expectant management
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Body Weight; Overweight
• Other Study ID Numbers: WINDOW

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

The final dataset will be publicly available in an anonymised form using an open data repository (i.e. CERN) or another equivalent database.

All relevant trial-related documents will be shared along with the data.

• IPD Sharing Time Frame: Beginning three months and ending three years after the publication of the last trial results.
• IPD Sharing Access Criteria: Data will be available for any research purpose to all interested parties who have approval from an independent review committee. Interested parties will be able to request the data by contacting the trial sponsor. Authorship of publications emerging from the shared data will follow standard authorship guidelines and will include authors from the WINDOW study group depending on the nature of their involvement.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No