Predictive factors for birth weight of newborns of mothers with gestational diabetes mellitus

Abstract

Aims: To evaluate the predictive factors of birth weight (BW) of newborns of women with gestational diabetes mellitus (GDM).

Methods: A cross-sectional study was performed among pregnant women with GDM treated in a public maternity unit, Brazil. We selected 283 pregnant women, with nutritional follow-up initiated till the 28th gestational week, singleton pregnancy, without chronic diseases and with birth weight information of the newborns. The predictive factors of BW were identified by multivariate linear regression.

Results: Mean maternal age was 31.2 ± 5.8 years; 64.4% were non-white; 70.1% were pre-gestational overweight or obese. Mean BW was 3234.3 ± 478.8 g. An increase of 1 kg of weight in the first and third trimesters increased BW by 21 g (p = 0.01) and 27 g (p = 0.03), respectively. Similarly, the other predictive factors of BW were pre-gestational body mass index (β = 17.16, p = 0.02) and postprandial plasma glucose in the third trimester (β = 4.14, p = 0.008), in the model adjusted by gestational age at delivery (β = 194.68, p < 0.001).

Conclusions: The best predictors of BW were gestational age at birth, and maternal pre-gestational and gestational anthropometric characteristics. Maternal glycaemic levels may also influence BW. The results may contribute to a review of prenatal routines for pregnant women with GDM.

Keywords: Birth weight; Gestational diabetes; Plasma glucose; Prenatal care; Weight gain.