Association of maternal obesity with foeto-maternal complications at delivery at the University of Teaching Hospital, Lusaka-Zambia

Obesity is increasing in pregnant women and at delivery and is associated with increased risk of instrumental delivery, operative delivery, macrosomia, shoulder dystocia, and poor foetal outcomes. This study aimed to determine the association of maternal obesity with maternal and foetal complications in labour for women delivering at the University Teaching Hospital in Lusaka, Zambia. Convenience sampling was used to recruit participants on admission to labour ward. An interviewer administered questionnaire and review of medical records were used to collect data that included sociodemographic characteristics, antenatal and delivery details and maternal and newborn outcome. There were 262 participants. More obese women (Body Mass Index – BMI >30) delivered by caesarean section or instrumental deliveries 21.4% compared with only 13.7% of those with normal BMI (18.5-25). Of those that delivered vaginally, 14.9% of the obese women had prolonged second stage compared with 10.9% of the normal weight women. Shoulder dystocia was significantly associated with obesity. Mothers who did not have shoulder dystocia had 94% reduced odds for obesity (OR 0.06, CI 0.01 – 0.44, P = 0.01). The average birth weight from the obese women was 3470g whilst the normal weight women delivered babies with an average birth weight of 3170g. Birth weight was significantly associated with obesity. Adjusting for age, knowledge of weight before pregnancy, birth outcome, and shoulder dystocia, the birth outcome was marginally significantly associated with obesity. Compared to live births, stillbirths had on average 6.5 times increased odds of being born from obese mothers (OR 6.5, CI = 0.96 – 44.08, P = 0.06). Birth weight is associated with maternal BMI and maternal obesity predisposes to prolonged second stage of labour and operative delivery, shoulder dystocia and stillbirths