RESUMO
AIMS: To identify predictive factors of birth weight (BW) of newborns of women with pregestational diabetes mellitus (DM). METHODS: Retrospective observational study with data from pregnant women who started prenatal nutritional monitoring up to 28 weeks, single pregnancy, and BW information. Quantitative variables were analyzed, and mean and standard deviation (SD) measures or medians and interquartile ranges (IQR) were calculated. Predictive factors were identified using multivariate linear regression. RESULTS: Eighty-six pregnant women were analyzed, 50% were diagnosed with type 1 DM, 46.5% with type 2 DM, and 3.5% with unclassified DM; 41% were mixed black and white, 35.6% had overweight and 33.3% had pregestational obesity. The mean BW was 3313.93 g (SD = 696.08). The predictive factors identified were: gestational weight gain (GWG) at the 3rd trimester (ß=60.42; p = 0.04), and gestational age at delivery (ß=194.03; p < 0.001); adjusted by time of diagnosis of DM (p = 0.07) and 1st-trimester glycated hemoglobin (p = 0.71). CONCLUSION: The best predictors of BW were gestational age at birth and maternal anthropometric gestational characteristics, which are modifiable variables. The results may contribute to a review of the prenatal routines of pregnant women with DM.