The use of tocolytics in cases of threatened preterm labor after 30 weeks does not improve the health of the baby. This is the conclusion of a large-scale study led by Amsterdam UMC. The idea behind tocolytic treatment is that delaying the birth gives the baby more time to develop in the womb, reducing the risk of health problems. However, the study shows that tocolytics have neither a positive nor a negative effect on the baby's health.
Globally, 1 in 10 pregnancies result in preterm birth. Children born prematurely have a higher risk of death and serious health problems both in the short and long term. Tocolytics have long been used as a standard treatment for women experiencing threatened preterm labor between 24 and 34 weeks. The idea is that delaying labor gives the baby extra time to develop in the womb, thus reducing the risk of health problems.
Martijn Oudijk, Professor of Obstetrics at Amsterdam UMC: “Until now, there has been no research backing whether prolonging the pregnancy with tocolytics improves the baby's health at birth.” In large hospitals in Canada and Ireland, tocolytics are not routinely used for threatened preterm labor after 30 weeks.
No Difference
The research, funded by the ZonMw program “Good Use of Medicines,” was carried out in 24 Dutch hospitals – part of the national research network of gynecologists (NVOG consortium) – as well as two hospitals in the UK and Ireland. 755 women with a threatened preterm labor between 30 and 34 weeks gave consent to be included in the study. Half of the women received tocolytics, while the other half received a placebo. Researcher Dr. Larissa van der Windt: “This is the largest placebo-controlled study worldwide examining the effect of tocolytics on baby health. We found no difference in the baby's health—neither positive nor negative.”
It’s Time to Reconsider
According to Oudijk, it is time to reconsider the current medical practice: “We need to question whether tocolytics should still be a standard treatment after 30 weeks. The goal of delaying birth is to give newborns a better start, but preterm birth often has a medical cause, such as an infection or problems with the placenta, where staying longer in the womb could actually be harmful. It’s high time that we, in the Netherlands, collaborate with other countries to adjust international guidelines,” concludes Oudijk.
The results were published today in The Lancet.