Vitamin D Deficiency Increases the Risk of Adverse Neonatal Outcomes in Gestational Diabetes

Background Gestational diabetes mellitus (GDM) and vitamin D deficiency have been associated with increased risk of adverse perinatal outcomes but the consequences of both conditions simultaneously present in pregnancy have not yet been evaluated. Our objective was to study the influence of vitamin D deficiency in neonatal outcomes of pregnancies with GDM. Methods 184 pregnant women with GDM referred to specialized prenatal monitoring were included in this cohort and had blood sampled for 25-hydroxyvitamin D measurement. Vitamin D was measured by chemiluminescence and deficiency was defined as < 20 ng/mL. Participants were followed until puerperium and adverse neonatal outcomes were evaluated. Results Newborns of women with vitamin D deficiency had higher incidences of hospitalization in intensive care units (ICU) (32 vs 19%, P = 0.048), of hypoglycemia (any, 17.3 vs 7.1%, P = 0.039 requiring ICU, 15.3 vs 3.6%, P = 0.008), and were more frequently small for gestational age (SGA) (17.3 vs 5.9%, P = 0.017). After adjustment, relative risk (RR) for hypoglycemia requiring ICU was 3.63 (95% CI 1.09-12.11) and for SGA was 4.32 (95% CI 1.75- 10.66). The incidence of prematurity, jaundice and shoulder dystocia was no statistically different between groups. Conclusions In this cohort of pregnant women with GDM, vitamin D deficiency was associated with a major increase in the incidence of adverse neonatal outcomes such as SGA newborns and neonatal hypoglycemia.