Does Fetal Testing Decrease Fetal Demise in Pregnancies Complicated by Obesity? [14E

Abstract

INTRODUCTION: Maternal obesity complicates over 30% of pregnancies, and is a risk factor for fetal demise (FD). Some have advocated increased fetal surveillance in pregnancies complicated by maternal obesity. The objective of this study is to determine if a protocol for fetal testing in obese women decreases the risk of FD. METHODS: This was a retrospective cohort study of women who delivered at Boston Medical Center, from 2006-2018, and deemed exempt by th IRB. FD rates in obese women (BMI≥30) with no other pregnancy complications, were compared to low risk pregnancies. Obese patients were scheduled for growth ultrasounds every 4 weeks and weekly fetal testing starting at 36 weeks. RESULTS: There were 3,037 women in the obese group, and 13,980 women in the uncomplicated group. There was no significant difference in FD between the two groups. The obese group had a fetal death rate of 3/1000 (n=10) after 24 weeks gestation, and 1/1000 after 36 weeks gestation (n=2) compared to a FD rate in the normal group of 5/1000 (n=66) after 24 weeks gestation and 2/1000 (n=31) after 36 weeks gestation. The obese group had an increased median number of fetal tests (4 vs 2, P<0.01), and cesarean deliveries (35% vs 24%, p<0.01). CONCLUSION: Despite a known increased incidence of FD in pregnancies complicated by obesity, a protocol of intensive antepartum fetal testing resulted in a FD incidence similar to a low risk population. This suggests that increased fetal testing should be offered for all pregnancies complicated by obesity.