[Radioimmunological determination of insulin in the amniotic fluid]

Small amounts of immunoreactive insulin, at about one-eighth the concentrations found in maternal serum, have been detected in human amniotic fluid. A positive correlation between term amniotic fluid insulin levels and newborn birth weight was found. Insulin was studied in 42 samples of amniotic fluid obtained from normal and pathological pregnancies by radioimmunoassay. In only one sample of amniotic fluid of diabetic mother with insulin dependence we found high values of insulin and condition of insufficient fetal lung maturity. We believe that radioimmunoassay of insulin in amniotic fluid may be a parameter of evaluation of fetal maturity.