RELATIONSHIP BETWEEN AMNIOTIC-FLUID INSULIN AND MATERNAL BLOOD-GLUCOSE CONCENTRATIONS IN PATIENTS WITH CARBOHYDRATE INTOLERANCE DURING PREGNANCY

In contrast to maternal blood glucose, amniotic fluid insulin (AFI) di rectly reflects the functional state of the fetal pancreas. In a prosp ective study we evaluated the correlation of AFI with maternal metabol ic control in 70 amniotic fluid specimens from 61 women having carbohy drate intolerance during pregnancy (White A n = 44, B0 n = 17). AFI wa s measured with the Insulin RIA 100 kit from Pharmacia (Freiburg). The normal range of AFI was established in 304 healthy pregnant women (16 th-42nd gestational week). AFI concentrations increased by a factor of 1.5 to 2 during gestation reflecting the maturation of the fetal panc reas. Elevated AFI levels (> 97th centile) were found in 11% of normog lycemic diabetics and in 500% of women with insufficient metabolic con trol. Despite a high overall concordance (81%) no direct relationship could be found between fetal and maternal parameters. Patients with in creased AFI values had a 5-fold higher rate of large-for-gestational a ge (LGA) infants than women with normal levels. This finding confirms the pathogenetic role of hyperinsulinism in the development of fetal m acrosomia.