Baseline Fetal Heart Rate at Term in Obese and Diabetic Women and Mode of Delivery [23J

Abstract

INTRODUCTION: Fetal heart rate (FHR) reflects adaptation to environment. Increased baseline FHR at term may be indicative of fetal inability to tolerate labor. This study reviews admission baseline FHR and mode of delivery when non-reassuring FHR is present. METHODS: A retrospective cohort study of 1,035 deliveries in obese mothers at term for 2016 was reviewed. Inclusion criteria included: body mass index (BMI) greater than 30, admission baseline FHR, and admission for delivery. Exclusion criteria included multiple gestation, congenital abnormalities, contraindications to labor, prior cesarean delivery and elective cesarean deliveries. Data extracted from medical record included: parity, medical conditions, admission diagnosis, admission baseline FHR, mode of delivery, and indication for cesarean delivery. Statistical analysis utilized Student's t-test and ANOVA for data stratification by BMI and diabetic status. RESULTS: Mean admission baseline FHR increased with BMI, diabetic status, and deliveries by cesarean delivery for nonreassuring tracing (NRFHRT). Vaginal delivery rate decreased with increasing BMI and presence of diabetic status. Student t-test of vaginal deliveries versus cesarean deliveries for NRFHRT was significant for diabetics with BMI between 30 and 34 (P<.01). ANOVA analysis of baseline FHR for all groups (P=.013) and all obese non-diabetics (P<.01) was significant; analysis for diabetics alone was not significant (P=.067). CONCLUSION: This study suggests baseline admission FHR significantly affects mode of delivery for obese mothers. In addition although not statistically significant, diabetic subgroups demonstrate a similar trend. Increased baseline FHR may be associated with decreased labor tolerance and increased cesarean delivery rate.