Incidence of fetal bradycardia and effect of placental injury on fetal heart rate during second-trimester genetic amniocentesis

Abstract

A prospective study was conducted for comparing the incidence of fetal bradycardia and level of fetal heart rate change following a second-trimester genetic amniocentesis with and without placental injury. A total of 257 and 495 participants in injured and non-injured groups were analysed. The incidence of fetal bradycardia following amniocentesis was not statistically different between the two groups (1.17%, [95% CI 0.24, 3.37] and 0.20%, [95% CI 0.005, 1.12]) in injured and non-injured placenta groups, respectively; p = 0.118). The mean change in baseline fetal heart rate before and after amniocentesis was also not significantly different between the two groups (p = 0.844). No fetal death or pregnancy loss occurred within 4 weeks after the procedure. All 4 bradycardia participants were normal and healthy and had an appropriate weight for their gestational age. We conclude that placental injury during a second-trimester genetic amniocentesis due to advanced maternal age poses only a low risk of fetal bradycardia, and there is no evidence of differences between subjects with injured and non-injured placenta in the changes in fetal heart rate.

Keywords::

• Amniocentesis
• bradycardia
• placenta injury
• fetal heart rate

Acknowledgements

The authors would like to thank the International Affairs Office, Faculty of Medicine, Prince of Songkla University, for their editorial assistance and Miss Walailuk Jitpiboon, Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, for her help with the statistical analysis.

Declaration of interest: No potential conflicts of interest were disclosed. The authors alone are responsible for the writing and content of the paper.