Gestational weight gain and birth weight of the newborn: a cross-sectional study in Jundiaí, São Paulo, Brazil

The aim of this study was to determine the prevalence of overweight, pre-pregnancy and gestational obesity and verify the association with the birth weight of the newborn. A descriptive cross-sectional study was conducted with 712 pregnant women admitted for delivery at the School of Medicine of Jundiaí hospital. The variables studied were socio-demographics, pregnancy, pre-pregnancy weight, prenatal care, total gestational weight gain and birth weight of the newborn. The majority (99.7%) had a pre-natal and 84.6% > 6 visits. The prevalence of pre-pregnancy overweight was 34.7%, and excessive total weight gain was 36.9%. A significant association was observed between the pregnant women's BMI classification and the newborn's weight (NB) classification and between total weight gain classification of the mother and the newborn's weight classification. In pregnant women with excessive weight a higher prevalence of newborns with appropriate weight was observed. In contrast, women with insufficient weight gain had 2.15 times higher risk of underweight newborns and 2.85 times higher risk of low weight newborns. Although a significant percentage of overweight pregnant women was observed, this influenced the insufficient weight of the pregnant woman though not the birth weight of the newborns.