Inducing pregnant women at 41 weeks is safer than waiting, trial suggests

It is safer to induce women with low-risk pregnancies at 41 weeks rather than “wait and see”, a trial suggests.

There was a lower risk of death when babies were induced at 41 weeks compared with waiting until 42 weeks to act, a trial in the BMJ found.

A pregnancy is considered full term when it reaches 37 weeks, according to the NHS.

Current practice in the UK and Scandinavia is to induce delivery for women who have not gone into labour by 42 weeks.

Researchers in Sweden compared the above “expectant management” approach with inductions offered at 41 weeks.

The trial involved 2,760 women with an uncomplicated, single pregnancy who were admitted to 14 Swedish hospitals between 2016 and 2018.

The researchers measured for a primary composite outcome that included factors such as stillbirth, death in the first few days of life, low oxygen levels, and breathing problems.

This was experienced at similar rates in both groups – by 33 women who were induced at 41 weeks and by 31 women in the group that waited.

But six babies in the expectant management group died compared with none in the induction group, so the trial was stopped early.

These were five stillbirths and one early neonatal death.

The researchers estimate that, for every 230 women induced at 41 weeks, one perinatal death would be prevented.

There was also a lower admittance to a neonatal intensive care unit in the group induced at 41 weeks.

The authors say differences in hospital policies and practices could have affected the results.

But they say women with low-risk pregnancies should be offered inductions “no later” than at 41 weeks and that “this could be one (of few) interventions that reduces stillbirth”.

In a linked editorial, Professor Sara Kenyon, professor of evidence based maternity care at the University of Birmingham, and colleagues say induction at 41 weeks “looks like the safer option for women and their babies”.

They add: “Choice is important within maternity care, and clear information about available options should be accessible to all pregnant women, enabling them to make fully informed and timely decisions.”

Professor Alexander Heazell, Consultant Obstetrician and Spokesperson for the Royal College of Obstetricians and Gynaecologists, said: “We are saddened by reports of babies who died during a research trial in Sweden. The loss of a baby is a devastating tragedy for parents, to the wider family, and the healthcare professionals involved.

“The findings of this Swedish trial are in line with what is already known – that pregnancies that continue to, or pass, 41 weeks are usually safe and straightforward, but there is a small yet significant increase in stillbirth risk.

“Current UK guidance recommends that induction of labour should be offered to women with uncomplicated pregnancies who go beyond 41 weeks to avoid the risks of prolonged pregnancy, including stillbirth.

“We support the continual review of clinical guidelines as new evidence emerges to ensure best practice.

“A woman’s individual needs and preferences should always be taken into account and they must have the opportunity to make informed decisions in partnership with their healthcare professionals.”