Relationship between amniotic fluid insulin and maternal blood glucose concentrations in patients with carbohydrate intolerance during pregnancy

Abstract

In contrast to maternal blood glucose, amniotic fluid insulin (AFI) directly reflects the functional state of the fetal pancreas. In a prospective study we evaluated the correlation of AFI with maternal metabolic control in 70 amniotic fluid specimens from 61 women having carbohydrate intolerance during pregnancy (White A n = 44, B0 n = 17). AFI was measured with the Insulin RIA 100 kit from Pharmacia (Freiburg). The normal range of AFI was established in 304 healthy pregnant women (16th-42nd gestational week). AFI concentrations increased by a factor of 1.5 to 2 during gestation reflecting the maturation of the fetal pancreas. Elevated AFI levels (> 97th centile) were found in 11% of normoglycemic diabetics and in 50% of women with insufficient metabolic control. Despite a high overall concordance (81%) no direct relationship could be found between fetal and maternal parameters. Patients with increased AFI values had a 5-fold higher rate of large-for-gestational age (LGA) infants than women with normal levels. This finding confirms the pathogenetic role of hyperinsulinism in the development of fetal macrosomia.

Amniotic fluid insulin levels identify the fetus at risk of neonatal hypoglycaemia

“…Crombach et al . [13] studied the relationship between insulin levels in amniotic fluid obtained at delivery and maternal blood glucose concentration in patients with IGT/mild GDM. Ten of 58 women had hyperinsulinaemic fetuses of whom four had macrosomic infants compared with four of 48 women in the normoinsulinaemic fetuses.…”

Zusammenhang zwischen Fruchtwasserinsulin im zweiten Trimenon, mütterlicher Glukosetoleranz und fetalen Fehlbildungen

“…Es handelt sich wahrscheinlich um einen physiologischen Anstieg mit zunehmender Reifung des fetalen Pankreas. [5,11,13].…”

“…Dies könnte darauf zurückzuführen sein, dass die Insulinwerte aufgrund weniger sensitiver Methoden in den frühen achtziger Jahren überbewertet wurden, währenddessen jetzt die spezifischeren RIA zum Einsatz kommen [9]. Zudem wurden in den anderen Studien auch Schwangere in höheren Schwangerschaftswochen eingeschlossen, und die Fallzahlen waren geringer [11,13]. Fruchtwasserinsulin und Fehlbildungen und chromosomale Anomalien Die beiden Feten mit den höchsten Fruchtwasserinsulinwerten im Studienkollektiv (9,0 mU/l und 8,0 mU/l) wiesen komplexe Fehlbildungen auf.…”