Antenatal fetal surveillance of women with severe obesity.

Objective: To estimate the impact of body mass index (BMI) categories on duration of the nonstress test (NST), and the need for additional tests of fetal wellbeing or interventions.

Methods: We conducted a retrospective cohort study of women with singleton pregnancies who had an NST for the indications of severe obesity (BMI ≥40 kg/m), diabetes (pre-gestational or gestational), hypertensive disorders (chronic, gestational, and preeclampsia), and others between 1 January 2015 until 31 December 2016. NST durations (<30 and ≥30 min) were compared between groups first based on BMI (kg/m) categories (<30, 30-39, 40-49, and ≥50) and then based on BMI and comorbidities: (1) severe obesity alone, (2) severe obesity and comorbidities, and (3) comorbidities alone.