Insulin levels in amniotic fluid and fetal growth.

Insulin concentrations in amniotic fluid were correlated with fetal age and with fetal weight in order to test the hypothesis that fetal insulin regulates fetal growth. No significant correlation could be detected. Insulin levels in amniotic fluid in diabetics, however, were significantly higher than in nondiabetics. In the same samples of amniotic fluid C-peptide proved to be very unstable during long term storage.