Induction of childbirth or waiting for the birth date to be exceeded? Researchers have evaluated 34 studies and see in one aspect a decisive advantage for the introduction.
Ingrid Kreutz Published: 16.07.2020, 4:56 p.m
The pregnancy is proceeding normally, but the calculated date of birth has already passed: When is the optimal time for induction of labor?
© Rudolf Polle / stock.adobe.com
Freiburg. If the pregnancy is otherwise normal but already past the calculated birth date, is it better to induce the birth or should one continue to wait? A controversial topic.
On the one hand, many people feel induction of labor is too much of an intrusion into the natural course of pregnancy. In this regard, there is also discussion of possible risks, such as whether induced births might be associated with a higher rate of sectiones or whether they have a higher risk of rare but serious complications.
On the other hand, there are also significant risks associated with missed term pregnancy or transfer, i.e. from two weeks after the due date, such as stillbirth or neonatal death.
These must be weighed against the risks of induction – an updated Cochrane Review on the topic is intended to help with this (Cochrane Database of Systematic Reviews 2020; online 15. July).
Based on 34 randomized controlled trials
This is an update of a review first published in 2006 and last updated in 2018, the Cochrane Germany Foundation (CDS) reports. The data base is now much broader than before and some of the conclusions have changed.
The review is now based on 34 randomized controlled trials from 16 different countries, involving a total of more than 21.500 women participated (mostly with low risk of complications). The studies compared the strategy of inducing labor, which usually occurs after 41 completed weeks of pregnancy ( 287 days), with a "watch and wait" strategy.
The evidence from the studies reviewed is mostly of high to moderate confidence on the four-point GRADE scale, where low and very low confidence are still possible, they say.
The authors’ conclusion: the current analysis shows a significant reduction in perinatal mortality with a strategy of induction of labor starting at 37. Week of pregnancy compared with a wait-and-see strategy (22 studies, 18.795 infants). Thus, there were four perinatal deaths in the group of children with induced birth, compared with 25 in the group with waiting. This equates to a relative risk reduction of 69 percent.
However, the absolute rates of perinatal deaths are small overall, at 0.4 versus 3 deaths per 1000 births.
Best time to induce labor still unclear
Rates of cesarean delivery were also lower in the induced-birth group, without increasing the proportion of vaginal deliveries (for example, using forceps or suction). The rate of admissions to neonatal intensive care units was also lower in this group.
No clear differences between induction of labor and waiting were found in the risk of perineal tears, postpartum hemorrhage, or prospects for successful breastfeeding at hospital discharge.
Whether the women were first-time or multiple birth mothers had no effect on the study results, according to the results of subgroup analyses.
It also remains unclear, based on the evidence to date, exactly when is the best time to induce labor, according to the authors of the Cochrane review.
Results of a Swedish study
However, not inducing labor in low-risk pregnancies until after 42 SSW is not advisable, according to the results of a Swedish study of 2760 women, because the perinatal mortality rate is increased in this case (BMJ 2019; online 20. November).
The Swedish researchers led by Dr. Ulla-Britt Wennerholm from Gothenburg now recommends, contrary to the previous practice in Sweden, that the mourning should begin as early as the 41st week of pregnancy. It is advisable to induce labor at the 20th week of pregnancy.
The German Society of Gynecology and Obstetrics recommends in its already expired guideline "Procedure in case of missed due date and transfer" to offer induction of labor in low-risk pregnancies "from 41+0 SSW, and to recommend it at the latest from 41+3 SSW". The guideline is currently being revised.