Effect of maternal beta-blocker treatment on mean fetal heart rate

Background

During pregnancy, the prescription of beta-blockers to the mother may be necessary for pre-existing chronic conditions. Their use raises concerns due to potential effects on the fetus.

Objectives

This study aimed to investigate the impact of beta-blockers on mean fetal heart rate in pregnant women treated with these medications compared to an untreated patient group.

Study Design

This was a retrospective case-control study involving 90 patients, divided into two groups: 45 patients on beta-blockers and 45 untreated patients. Included patients delivered singleton pregnancies after 24 weeks of gestational age at two university hospitals in Île-de-France between 2009 and 2021. They were matched based on age, parity, and gestational age at delivery. Fetal heart rate and maternal heart rate were recorded on the day of delivery. Pregnancy outcomes were studied secondarily.

Results

There was no significant difference in mean fetal heart rate between the two groups: 87% of fetuses from mothers treated with beta-blockers had a heart rate between 110 and 150 bpm, compared to 93% of fetuses in the second group (P=.71). Among patients taking beta-blockers, the most commonly used treatment was bisoprolol.

Conclusion

The study did not reveal a significant effect of beta-blockers on fetal heart rate. However, close monitoring and appropriate clinical management are still necessary for pregnant patients on beta-blocker treatment due to other potential implications like intra-uterine growth restriction for both the mother and the fetus.