Incidence of large for gestational age infants when gestational diabetes mellitus is diagnosed early and late in pregnancy

AimsTo compare the incidence of large-for-gestational-age (LGA) infants in women diagnosed with gestational diabetes mellitus (GDM) early and late in pregnancy, and evaluate associated factors. MethodsA total of 284 women with GDM who commenced antenatal care before 20 weeks of gestation were enrolled: 142 were diagnosed before 20 weeks (early GDM) and 142 were diagnosed after 20 weeks of gestation after normal initial screening tests (late GDM). Incidence of LGA infants were compared. Factors associated with LGA and pregnancy outcomes were evaluated. ResultsBoth groups had comparable baseline characteristics. The late GDM group were more likely to gain weight greater than recommended (P = 0.009) and less likely to have optimal glycemic control (P = 0.035). Incidences of maternal and neonatal complications, including LGA, were not significantly different between the groups. Logistic regression analysis demonstrated that the timing of GDM diagnosis was not significantly associated with LGA. Less gestational weight gain than recommended decreased the risk of LGA by 76% (adjusted odds ratio [OR] 0.24, 95% confidence interval [CI] 0.09-0.67, P = 0.007), while gestational weight gain greater than recommended doubled the risk of LGA (adjusted OR 1.99, 95% CI 1.03-3.87, P = 0.041). Good glycemic control also reduced the risk of LGA by 66% (adjusted OR 0.34, 95% CI 0.16-0.71, P = 0.886). ConclusionGestational weight gain and glycemic control, but not timing of diagnosis, were independently associated with LGA in women with GDM. Women diagnosed with GDM early had similar rates of LGA infants as women diagnosed late.