WILL - When to Induce Labour to Limit risk from high blood pressure in pregnancy
The WILL trial aims to find out if it is safer for women who have high blood pressure during pregnancy to have their babies delivered slightly early, or to let the pregnancy carry on as usual.
High blood pressure during pregnancy can lead to complications for women and babies. Currently, most pregnant women with high blood pressure at 40 weeks are offered an induction (artificially starting labour using hormones) or Caesarean section to reduce the risks of continuing with the pregnancy. It is possible that delivering the baby before 40 weeks could reduce the chance of health problems and stillbirth. But it is also possible that an early delivery could increase the chance of complications for the baby.
This trial is testing whether planned delivery at 38 weeks is better overall than monitoring the woman and unborn baby until at least 40 weeks. The research team are also interested in finding out if there is any link between the two different times of delivery and the baby’s health and their wellbeing in later life, such as how well they perform at school.
Find out more below and explore the WILL trial website.
More information
Why is this research needed?
High blood pressure during pregnancy can lead to complications for women and babies. Currently, most pregnant women with high blood pressure at 40 weeks are offered an induction (artificially starting labour using hormones) or Caesarean section to reduce the risks of continuing with the pregnancy. It is possible that delivering the baby before 40 weeks could reduce the chance of health problems and stillbirth. But it is also possible that an early delivery could increase the chance of complications for the baby.
What are the aims of the research?
This trial is testing whether planned delivery at 38 weeks is better overall than monitoring the woman and unborn baby until at least 40 weeks. The research team are also interested in finding out if there is any link between the two different times of delivery and the baby’s health and their wellbeing in later life, such as how well they perform at school.
What will the researchers do?
During the trial women will be randomly put into two different groups: one for planned delivery of the baby at 38 weeks gestation, the other for monitoring the pregnancy until 40 weeks. This ensures that a fair comparison of the two groups can be made. The research team will analyse any differences between the number of health problems or stillbirths in each group to see whether planned delivery at 38 weeks does reduce these risks or not.
Sands has supported the research team in the design of this study and was closely involved in highlighting the importance of finding a balance between minimising risks of health problems from delivering a baby early and reducing the risk of stillbirth from continuing pregnancy. Along with Action on Pre-Eclampsia (APEC), Sands has helped to set up a Parent Advisory Group so that parents can help to support the research team throughout the project.
What is the study expected to find?
We anticipate that the results of the trial will help the growing number of women with high blood pressure and their midwives and doctors make decisions about timing of delivery, with the overall aim of reducing the number of health problems for women and babies and the number of stillbirths.
Additional information
Lead researcher – Professor Laura Magee
Institution – King’s College London
Funder – National Institute for Health Research (NIHR)
Duration – May 2018 - July 2022