The Impact of Antenatal Testing for Advanced Maternal Age on Cesarean Delivery Rate at an Urban Institution

Abstract

The birth rate for women over the age of 40 continues to increase with a rate of 11 births per 1,000 women in 2011.1 Advanced maternal age (AMA) has been associated with an increased riskof stillbirth2–5 even after controlling for risk factors such as hypertension, diabetes, and multiple gestation.2,3 While Fretts et al found an increase in the stillbirth rate among women older than 35 years of age, this rate was significantly higher in women over the age of 40.3 A 2.4-fold increased rate of stillbirth among women 40 years old or greater was noted when compared with women less than 40 years old.3 While the risk of stillbirth increases after 38 weeks for all age groups, Reddy et al noted that it was most remarkable in women over the age of 40, with a hazard of death of 2.5 per 1,000 for ongoing pregnancies in this age category.2 Given the known association of AMA and stillbirth, with a greater risk noted after the age of 40, antenatal testing guidelines have been implemented at many institutions based on maternal age greater than 40 years old. It is plausible that antenatal testing may lead to a higher rate of medical intervention including a higher rate of induction of labor and cesarean delivery. While a higher induction and cesarean delivery rate may be acceptable when the intervention is thought to prevent stillbirths, it is important to understand the implications that antenatal testing has in the AMA population to better counsel our patients. The objective of this study was to evaluate the rate of cesarean delivery and induction of labor among women of AMA who had antenatal testing for AMA compared with those who delivered before the implementation of antenatal testing for AMA. Our hypothesis was that women who undergo antenatal testing for AMA have higher cesarean delivery and induction rates.