Abstract:Study objective is to study the influence of early pregnancy BMI on neonatal birth weight. To Study the association between gestational weight gain and neonatal birth weight. An observational correlational study, consisting of 1031 pregnant women, with singleton uncomplicated pregnancy, booked at Krishna Institute of Medical Sciences, Karad before 12 weeks of pregnancy, conducted between June 2014 to December 2015. After getting written informed consent from the patient, patients included in the study. Those who developed any complication during the study were excluded. With rising BMI, weight gain in pregnancy is greatly increased. Maternal pregnancy BMI has a positive association with the birth weight of neonatal. Lower BMI is significantly linked to a relatively low weight gain lower birth weight.