Impact of gestational diabetes on neonatal outcomes: a retrospective cohort study

Aims: To assess neonatal outcomes in pregnant women with positive diagnosis of gestational diabetes mellitus (GDM). Methods: Retrospective cohort study of 522 postpartum women, among whom 255 presented with GDM, diagnosed in accordance with the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria, and 267 did not have GDM. The patients in the latter group were randomly selected. Associations were established between GDM and adverse neonatal outcomes, including prematurity, macrosomia, low Apgar score, neonatal hypoglycemia, and admission to a neonatal intensive care unit. Maternal characteristics such as age, pre-gestational body mass index, weight gain, parity, and mode of delivery were also analyzed for the adjustment of confounding factors. After confirming the normal distribution of the assessed characteristics, the quantitative variables were analyzed by Student's t test and the qualitative ones by the chi-squared test. The data on the effect of GDM on perinatal outcomes were presented as relative risks using contingency tables, and robust Poisson's regression models were used to adjust the confounding variables Results: Newborn infants of women with GDM had a higher risk of preterm birth (relative risk [RR] 2.3; 95% confidence interval [95% CI] 1.1-5.0), macrosomia (RR 1.6; 95% CI 1.1-2.5), and neonatal hypoglycemia (RR 4.2; 95% CI 1.4-12.3). The relationship between GDM and low one-minute and five-minute Apgar scores was not significant (RR 1.9; 95% CI 0.9-3.8 and RR 2.1; 95% CI 0.4-11.3, respectively). There was no significant increased risk of admission to the neonatal intensive care unit (RR 1.4; 95% CI 0.6-3.2). Conclusions: The risks of prematurity, macrosomia, and neonatal hypoglycemia were higher in pregnant women with GDM diagnosed according to the IADPSG criteria.