Introduction: Maternal obesity has been associated with adverse pregnancy outcomes, such as preeclampsia, eclampsia, pre and post term delivery, increased rate of caesarean section.

Objectives: To find out the effect of increasing body mass index (BMI) on pregnancy outcomes in nulliparous women delivering singleton babies. Method: This was a hospital based observational study, based on 300 nulliparous women delivering singleton babies in june(2017) to dec (2018). Women were categorized into four groups. Underweight (BMI< 20kg/m2) , normal (BMI 20-25 kg/ m2), overweight (BMI 25-30 kg/ m2), and obese BMI >30 kg/m2. Obstetric Outcome compared by univariate and multivariate analysis.

Results: Maximum no. of patients who underwent L.S.C.S (40%) were having B.M.I > 30 kg/ m2. L.S.C.S. with C.P.D, Postdatism and post – L.S.C.S wound infection was maximum (44%),(32%) and (22%) for B.M.I > 30 kg/m2. Maximum no. of patients with Pre- eclampsia (38%)were having BM.I. between 25- 29.9 kg/m2.

Conclusions: Increasing BMI is associated with increased incidence of cesarean delivery, Pre-eclampsia and preterm delivery and post datism.

Keywords: BMI; Innulliparous Women; Singleton pregnancy.