Towards national comprehensive gestational diabetes screening - consequences for neonatal outcome and care.

INTRODUCTION: The change from risk-factor-based to nearly comprehensive screening of gestational diabetes (GDM) identifies more but milder cases of the disease. The main aim of this study was to evaluate the effect of this screening policy change on neonatal outcomes and care.

MATERIAL AND METHODS: A population-based register study in Finland. GDM cases during risk-factor-based (year 2006, n = 5179) and comprehensive (2010, n = 6679) screenings were identified through the Medical Birth Register. All singletons without maternal GDM or prepregnancy diabetes served as controls (n = 51 746 and n = 52 386, respectively). The main outcomes were macrosomia, neonatal hypoglycemia and the need for care in a neonatal ward.

RESULTS: In the GDM group, the mean birthweight decreased between the study years from 3660 g to 3595 g and the prevalence of macrosomia from 5.6 to 4.1% even after adjustment for maternal age, parity and prepregnancy body mass index. The adjusted mean difference in birthweight between GDM and control newborns decreased from 70 to 22 g between the study years. The prevalence of neonatal hypoglycemia increased from 18.0 to 22.1% in the GDM group. However, neonatal hypoglycemia was more often treated without care in a neonatal ward. The proportion of infants treated on a neonatal ward decreased in both the GDM and control groups between the study years.

CONCLUSIONS: In newborns, comprehensive GDM screening led to decreased mean birthweight and macrosomia rates, but the prevalence of neonatal hypoglycemia increased. This places substantial demands for delivery hospitals and healthcare resources.