Large-for-gestational-age newborns in women with insulin-treated gestational diabetes under strict metabolic control.

OBJECTIVE: To assess the influence of strict metabolic control in women with insulin-treated gestational diabetes on the risk of large-for-gestational-age (LGA) newborns, the frequency of obstetrical complications and fetal outcome.

METHODS: In this prospective cohort study, 875 women were screened for gestational diabetes mellitus with a 75 g oral glucose tolerance test (OGTT) between weeks 24 and 28 of gestation. The study group (n = 162) consisted of women with insulin-treated gestational diabetes mellitus (GDM) and the control group (n = 713) of women with normal glucose tolerance (NGT). In the women with diabetes, strict adjustments of fasting glucose levels to 90 mg/dl and 130 mg/dl postprandially were achieved with insulin administration.

RESULTS: No increased risk for LGA newborns was observed in women with GDM and good metabolic control (16.7% vs. 12.3%; p = 0.1). In women with NGT, maternal prepregnancy BMI was significantly higher in those who delivered LGA newborns than in those who gave birth to newborns below the 90th percentile [27.2 kg/m(2) (5.0) vs. 24.4 kg/m(2) (5.6); p = 0.006], whereas there was no influence of maternal BMI on birth weight of newborns in women with GDM. There was no difference between the two groups with respect to maternal birth traumata and fetal outcome, except for plexus palsy which occurred in three GDM women with macrosomic newborns.

CONCLUSION: Strict metabolic control and surveillance in women with insulin-treated GDM seems to attenuate the risk for LGA newborns, diabetic fetopathia, and the influence of maternal BMI on fetal growth.