Women with gestational diabetes who have very elevated fasting blood glucose levels appear to be at an increased risk for fetal macrosomia and perinatal complications if treatment is not provided,5 but the association of milder forms of gestational diabetes with such outcomes has been unclear.
The recent Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study, however, described a strong continuous association between maternal glucose concentrations and increasing birth weight, cord-blood serum C-peptide levels, and other markers of perinatal complications, even at glucose concentrations below those that are usually diagnostic of gestational diabetes mellitus.