Amniotic Fluid Content of Glucose, C-Peptide and Insulin in Normal and Diabetic Pregnancies

Summary

Glucose, C-peptide and insulin concentrations in amniotic fluid were measured in 63 women, 19 of whom had insulin-dependent diabetes. The amniotic fluid glucose concentration was higher in the diabetic (37.4 ± 4.1) than in the normal women (19.4 ± 5.1 mg/dl; P < 0.01). The amniotic fluid insulin concentration was higher in diabetic than non diabetic women (15.9 ± 3.1 versus 8.9 ± 2.1 μU/ml;P < 0.01). The C-peptide concentration was also higher in the amniotic fluid of diabetic women than normal (1.60 ± 0.66 vs 0.26 ± 0.15 nmol/l; P < 0.001).

The lecithin/sphingomyelin (L/S) ratio in the amniotic fluid was greater than 2 in 61 mothers; only two diabetic patients had an L/S ratio lower than 2. Five neonates of diabetic mothers were macrosomic and three of these were also hypoglycaemic.

A negative correlation was observed in diabetic women between insulin and C-peptide concentrations in the amniotic fluid and apgar score of the newborn infants both at 1 and 5 minutes; no correlation was found on the contrary with the amniotic glucose.

In the prognostic evaluation of the fetus with a diabetic mother one must consider many parameters. Among these more consideration must be given to the levels of C-peptide and insulin in amniotic fluid than to glucose level.

Key-Words:

Amniotic Fluid - Insulin - C-Peptide - Glucose - Diabetic Pregnancies - Apgar Score