[Impact of HAPO study findings on future diagnostics and therapy of gestational diabetes].

Abstract

The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study is a trial on a high evidence level that included 25,000 women recruited in 15 centers all over the world who underwent a 75-gram oral glucose tolerance test (oGTT) at 24-32 weeks of gestation. Data remained blinded if the fasting plasma glucose level was below 105 mg/dl (5.8 mmol/l) and the 2-hour plasma glucose level was below 200 mg/dl (11.1 mmol/l). The aim of the study was to clarify whether maternal hyperglycemia less severe than that in diabetes mellitus is associated with increased risks of adverse pregnancy outcomes. The results indicate a continuous association of maternal glucose levels below those diagnostic of diabetes with an adverse outcome, with the strongest risk for increased birth weight and cord blood serum C peptide levels indicating fetal hyperinsulinism. Additionally an increased risk for maternal complications like preeclampsia was seen. Like in many biological processes, there were no obvious thresholds at which risks increased. An international expert committee proposed how to transfer the HAPO data into criteria for the oGTT in pregnancy for the future diagnosis of gestational diabetes mellitus (GDM) which will be based on acute pregnancy problems in contrast to the recent Carpenter and Coustan criteria. The availability of uniform, internationally accepted and applied GDM criteria will provide more clinical and legal security for the caregivers which will be a big advantage also in Germany where a wide diversity of GDM criteria is used. Beside the threshold discussion, the HAPO data are of enormous relevance for Germany. The HAPO data will significantly influence the decision of the German Health Authorities whether to finally establish a general screening for GDM as obligatory part of prenatal care. A report from the German Institute for Quality and Efficiency in Health Care (IQWiG) which was ordered from the German Health Authorities describes--mainly based on the HAPO Study--an indirect benefit of blood glucose screening for GDM for all pregnant women.