Context:Inadequate prenatal weight gain is a significant risk factor for adverse maternal and fetal outcomes. Nutrient intake and weight gain during pregnancy are the two main modifiable factors influencing maternal and infant outcomes.Aim:To assess the social and demographic factors affecting weight gain of pregnant women and to determine the correlation between maternal weight and fetal outcome.Setting and Design:Observational prospective study.Materials and Methods:Two different groups and settings of populations were studied, one enrolled in the antenatal clinic of a tertiary care hospital (sample size 197) and the other suburban antenatal clinic located in a slum community (sample size 97) of the same metro city.Statistical Analysis:Chi-square test, Fisher's exact test, and Pearson's correlation coefficient were used for analysis.Result:In the tertiary care hospital, 16.75%, 75.13%, and 8.12%, whereas in the suburban hospital 47.42%, 46.39%, and 6.19% primigravidae gained less than or equal to 8, 8.1–16 kg, and more than 16 kg weight, respectively. In the tertiary care hospital, the percentages of preterm birth, low birth weights, special attention needed, and no immediate cry after birth were 5.1%, 19.80%, 4.1%, and 4.1%, respectively, while in the urban health center they were 9.3%, 41.24%, 21.65%, and 11.3%, respectively. A significant association was found between maternal weight gain and birth weight of neonate and special attention needed by baby in both groups.Conclusion:Monitoring the maternal weight during the antenatal period epidemiologically determines the strength of association between maternal weight gain and birth weight of child.