Correlation of pre pregnancy BMI and gestational weight gain with fetomaternal outcome: An observational study

Abstract

Background: Gestational weight gain (GWG) is a crucial determinant of maternal and neonatal health. Both inadequate and excessive GWG are associated with adverse outcomes. The Institute of Medicine (IOM) guidelines recommend weight gain ranges based on pre-pregnancy body mass index (BMI). This study aimed to evaluate the correlation between GWG and fetomaternal outcomes across different BMI categories among women delivering at a tertiary care hospital in North India. Methods: A retrospective observational study was conducted in the Department of Obstetrics and Gynaecology, Rohilkhand Medical Research Institute (RMCH), Bareilly, from March 2024 to March 2025. Medical records of 350 pregnant women were reviewed. Data regarding age, parity, BMI, GWG, obstetric complications, labour, and neonatal outcomes were collected. GWG was classified according to IOM recommendations as poor, normal, or excessive. Associations between GWG, BMI, and outcomes were analyzed using the chi-square test, with p<0.05 considered statistically significant. Results: The majority of women (97%) were aged 19-35 years; 40.6% were primipara. Based on BMI, 26.3% were underweight, 52.6% normal, 14.6% overweight, and 6.6% obese. Inadequate GWG occurred in 56%, normal GWG in 31%, and excessive GWG in 13%. Poor GWG was linked with preterm labour (10.5%), low birth weight (39%), and anaemia (43%), while excessive GWG was associated with GDM (5%), hypertensive disorders (6%), and increased LSCS rate (36%). Most deliveries occurred at term (?78%). Conclusions: GWG closely followed pre-pregnancy BMI trends. Excessive GWG and high BMI were linked to metabolic and obstetric complications, whereas below-recommended GWG increased risks of anaemia, preterm delivery, and low birth weight. Integrating BMI assessment and individualized nutritional counselling into antenatal care can improve fetomaternal outcomes.