Objectives: To assess insulin resistance and sensitivity during pregnancy and find its correlation with maternal and fetal outcomes. Design: Prospective observational pilot study Setting: Department of Obstetrics & Gynaecology, AIIMS, New Delhi. Sample size and population: 154 singleton pregnant women between 18- 40 years of age attending the outpatient antenatal clinic of the Department of Obstetrics and Gynaecology, All India Institute of Medical Sciences, New Delhi and following the inclusion and exclusion criteria were recruited after taking informed consent. Materials and methods: A two-year prospective observational study at XYZ, enrolled 154 pregnant women, following 113 until delivery. Insulin resistance was assessed twice using HOMA IR and HOMA-β, and GDM was tested by OGTT. Main Outcome Measures: Maternal outcomes: Preeclampsia, Gestational hypertension, Chronic hypertension, polyhydram-nios, postpartum hemorrhage and puerperal sepsis. Fetal outcomes: birth weight, occurrence of hypoglycaemia, Transient tachypnoea of newborn, hyperbilirubinemia and NICU admissions. Results: In our study, 17.7% of women were diagnosed with GDM. Significant correlations were found between BMI and insulin resistance (p=0.001), and family history of diabetes and insulin resistance (p=0.001). HOMA-IR ≥2.5 at 24-28 weeks increased the likelihood of GDM (p=0.014), preeclampsia (p=0.043), and caesarean sections (p=0.009). HOMA-IR <2.5 indicated healthier pregnancies (p=0.034). HOMA-β ≤184.1 was linked to adverse fetal outcomes and NICU admissions (p=0.012). Conclusions: Optimizing BMI before pregnancy reduces risks like GDM, preeclampsia, NICU admissions, and neonatal hypoglycemia. Promote lifestyle, diet, exercise, and weight control awareness.