Effect of Maternal Body Mass Index on Intrapartum and Neonatal Outcome in Nulliparous Women in North Karnataka: A Prospective Cohort Study

Abstract

Introduction: Nutrient intake and weight gain are the two main modifiable factors during pregnancy that influence maternal and infant outcome. Body Mass Index (BMI) derived from weight and height is a marker of metabolic and endocrinal status and is used to classify people from underweight to obese. Pregnancy complications related to maternal BMI is a growing problem. Both lean and obese mothers carry an increased risk of adverse perinatal outcome. Aim: To assess the effect of maternal BMI on labour and mode of delivery, neonatal outcome and to detect the obstetric complications in relation to different BMI’s. Materials and Methods: A prospective study was conducted in Mahadevappa Rampure Medical College, Kalaburagi, Karnataka, India, from August 2014 to July 2016 in which total of 200 primigravidas with singleton pregnancy; in labour after 28 weeks of gestation were included. BMI was calculated using the formula by Quetelet. The women were categorised into underweight, normal, overweight and obese according to World Health Organisation (WHO). Results: Out of 200 cases, 111 (55.5%) were of normal BMI, 61 (30.5%) overweight, 16 (8.0%) obese and 12 (6.0%) underweight. Pre-eclampsia, oligohydramnios, Intrauterine Growth Restriction (IUGR), anaemia, foetal birth weight <2.5 kg, increased incidence of Neonatal Intensive Care Unit (NICU) admissions and early neonatal complications were commonly seen in underweight which was statistically significant (p<0.01). Gestational hypertension (n=5), increased incidence of caesarean sections (n=13), foetal birth weight >3.5 kg (n=5), failed spinal anaesthesia (n=2), postpartum haemorrhage (n=4), post Lower Segment Caesarean Section (LSCS) wound gape (n=2) and prolonged hospital stay (n=3) were the complications seen in obese individuals. Conclusion: Maternal BMI showed a strong association between pregnancy complications and outcomes. Therefore, all the pregnant women need to be advised to maintain normal BMI in order to achieve a healthy outcome as both underweight and obese women carry risk for adverse pregnancy outcome.