Many people are told that if their waters break (and they’re full term) that they will need to be induced after 24 hours if their contractions don’t start and they don’t go in to labour. This guideline is said to be because of the risk of infection. But where does this 24 hour clock come from and is it accurate?
The advice to induce within 24 hours is based on research from the 1950’s and 1960’s when stillbirth rates were extremely high when a mother experienced premature rupture of membranes (PROM) at full term. However, these studies didn’t factor in:
deaths due to botched forceps deliveries
deaths due to declined caesareans
deaths due to refusal of care if you were black
deaths due to no antibiotic treatment
deaths due to premature birth (term PROM and pre-term PROM were not separated out)
Modern research studies show waiting for up to 48-72 hours after the water breaks does not increase the risk of infection or death to babies who are born to mothers who meet certain criteria.
If left to go in to labour naturally, 45% of people go into labour within 12 hours and 77% to 95% will go into labour within 24 hours. In another large study, 76.5% of people with term PROM went into labour within 24 hours, and 90% were in labour within 48 hours (Pintucci et al., 2014).
Vaginal exams and sweeps can both be a cause PROM, as well as a source of infection.
One study looked at the frequency of vaginal exams and PROM and found that those having weekly vaginal exams starting at 37 weeks had a three times higher chance of having PROM (18%) compared to those who had no weekly exams until 40 or 41 weeks (6%) (Lenihan, 1984).
The TERM PROM study found women who had PROM and had 3-4 vaginal exams were twice as likely to develop infection, and this risk increased with the number of VEs.
In another study, women who were more than 1 centimeter dilated and had a sweep were significantly more likely to develop PROM (9.1% vs. 0%).
So, key points are:
Inducing with oxytocin for term PROM may reduce the chance of maternal infection, but does not have an effect on newborn infections.
Avoiding vaginal exams is one of the most significant ways to reduce the chance of infection after PROM.
The research shows you can wait for up to 2-3 days for labor to begin on its own.
Due to access to modern antibiotics, the “24-hour clock” for giving birth is outdated advice and no longer based on evidence.
There is a very detailed article on the evidence based birth website I highly recommend reading, which breaks down the research. Advice on whether induction is truly the best option will depend on your individual circumstances and any signs of infection. You can read the article and the research behind my post here.
Wondering what else you’ve been told that isn’t evidence based? Get yourself on to one of my courses and let’s dispel those myths and make sure you’re fully prepped for labour! Contact me to reserve your place and let’s get you prepped for the birth of your baby!