Abstract BACKGROUND – Insulin resistance and profound changes in body weight are common features of pregnancy. Obesity in pregnant women and glucose intolerance due to insulin resistance, ultimately leading to Gestational Diabetes Mellitus (GDM), both can add to poor maternofetal outcome such as, macrosomia, prematurity, shoulder dystocia, preeclampsia, and even increased chances of fetal demise. Leptin is a novel potential regulator of insulin resistance. Measuring serum leptin levels in pregnant women with different BMI categories may potentially help in early detection of GDM, and predicting poor maternofetal outcome at early stages of pregnancy. OBJECTIVES 1. To study serum leptin levels in women with GDM 2. To study the body mass index in women with GDM and classify study subjects according to BMI 3. To study the serum leptin levels in women with GDM belonging to various BMI categories and evaluate its association 4. To correlate serum leptin and BMI with materno-fetal outcome in women with GDM METHODOLOGY – This prospective hospital based study will be conducted in department of obstetrics and gynecology, at Acharya Vinoba Bhave Rural Hospital (AVBRH). 96 pregnant women seeking care at outpatient unit and/or in patient unit of Obstetrics & Gynaecology, in the AVBRH hospital, Sawangi, Meghe, in first trimester, will be included in the study. Screening for GDM in twice, first as soon as possible after diagnosis of pregnancy (first trimester) and second between 24-28 weeks, fasting Serum Leptin will be measured at 28 -32 weeks of gestation. EXPECTED RESULT - It is expected that levels of Sr. Leptin will be higher in the women with GDM and will be abnormal in various BMI categories with a proportionate rise with increasing BMI.