Effect of prepregnancy body mass index and gestational weight gain on birth weight.

OBJECTIVE: Nutritional status of women has been considered an important prognostic indicator of birth outcome. The study aims to show the effect of various prepregnancy Body Mass Index (BMI) categories and corresponding gestational weight gain on newborn birth weight. METHODS: Two hundred women were included in the study. These women had regular antenatal visits and later delivered at The Aga Khan University Hospital (AKUH) between the period January 1, 1996 to December 31, 1997. RESULTS: For women with prepregnancy BMI < 19., mean birth weight of newborns was lower for those gaining < 12.5 kg than those gaining > 12.5 kg (P < 0.001). Women who started their pregnancy with BMI 19.8-26 and gained weight above expected range gave birth to high birth weight babies (P = 0.009). Gestational weight gain did not have a significant association with birth weight for women having prepregnancy BMI > 26. CONCLUSION: Efforts should be made to attain adequate prepregnancy weight to reduce the likelihood of low birth weight babies. Hence, special attention should be paid to women with low prepregnancy BMI.