The extended Pedersen hypothesis.

The Pedersen hypothesis of fetal macrosomia in neonates born to diabetic mothers has been extended. In neonates born to gestational diabetic mothers, it is suggested that an intrinsic fetal pancreatic beta-cell hyperplasia 'pulls' glucose across the placenta, i.e. assists in glycemic control of the mother. The initial increase in fetal size due to fetal hyperinsulinism gives rise to developing hypoxemia, and the limitation in fetal oxygen availability alters differential tissue utilization of glucose, increases alpha-glycerophosphate synthesis in fetal adipocytes, and gives rise to a further increase in fetal adiposity.