WILL - When to Induce Labour to Limit risk in pregnancy hypertension
Research type
Research Study
Full title
When to Induce Labour to Limit risk in pregnancy hypertension – a multicentre, randomised controlled trial
IRAS ID
252294
Contact name
Laura A Magee
Contact email
Sponsor organisation
Kings College London
Clinicaltrials.gov Identifier
n/a, n/a
Duration of Study in the UK
3 years, 6 months, 31 days
Research summary
Research Summary
There is little information to guide doctors and women with high blood pressure when they make decisions about timing of delivery. Most pregnant women with high blood pressure are offered delivery at 40 weeks of pregnancy if they have not already gone into labour on their own, had a booked Caesarean section, or developed problems that made delivery necessary before 40 weeks.
Our study will run for 3 years in 30 UK hospitals. We will ask women to take part if they have reached 36 weeks of pregnancy and have high blood pressure that developed before or during pregnancy without other current problems. If women consent and are still pregnant at 37 weeks, women will have either: (1) a planned delivery at 38 weeks (by labour induction or elective Caesarean as would usually be done in their hospital) or (2) monitoring until at least 40 weeks, when the baby will be delivered if the woman has not already gone into labour, had an elective Caesarean, or there was another medical reason for an earlier delivery. Women will be put into group (1) or (2) at random. For women in both groups, doctors and midwives will provide normal care before and after birth.
The main aim of the study is to see if planned delivery at 38 weeks, compared with monitoring until at least 40 weeks, can reduce problems for the mother without causing problems for the baby that would separate him/her from the mother. Also, we want to see whether planned delivery at 38 weeks (compared with monitoring until at least 40 weeks) can reduce the need for Caesarean delivery, and the number of babies dying before birth. We will ask women if we can link delivery data with routinely-collected health/school census data for future study.
Summary of Results
Why did we do this trial?
Pregnant women often develop high blood pressure late in pregnancy. This can lead to serious problems for mothers and babies. Early birth would likely prevent some harms for mothers, but may damage babies in other ways. This study tested whether planned birth two weeks before the due date (compared with ongoing monitoring) could reduce problems for mothers without causing problems for babies.
What did we do?
Women with high blood pressure and no other problems were invited at 36 weeks of pregnancy. Those who agreed were put into one of two treatment groups, randomly. One group had planned birth at 38 weeks, by labour induction or Caesarean according to their choice. The other group received expectant care (‘watchful waiting’) until labour started, or they reached at least their due date or another date recommended for birth by usual hospital policy, or they developed a problem which meant birth was needed.
We planned to recruit 1080 women to show small differences between the two groups. However, enrolment was slow and affected by the COVID pandemic, so the funder stopped the trial after 403 women had joined.
What did we find?
Most women had labour induced, even in the expectant group. Overall, for women with well-controlled high blood pressure, delivering babies at around 38 weeks seemed to be safe. The early birth group experienced a similar number of serious complications for mothers, but they were less likely to develop a serious condition called pre-eclampsia. Importantly, giving birth earlier didn’t affect the baby’s need for extra care, and Caesareans were not increased. Also, the early birth group had fewer antenatal visits and tests, which saved the NHS £407.80 per woman.
What does this mean?
These results will help women make informed decisions and healthcare systems plan services.REC name
London - Fulham Research Ethics Committee
REC reference
18/LO/2033
Date of REC Opinion
3 Dec 2018
REC opinion
Favourable Opinion