Amniotic Fluid C-Peptide and Cortisol in Normal and Diabetic Pregnancies and Pregnancies Accompanied by Fetal Growth Retardation

ABSTRACT

The interrelationship between amniotic fluid (AF) concentration and content (AF × cone) of C-peptide and cortisol was studied in four groups of women comprising 10 gestational and 16 type-l diabetics, 11 women with intrauterine growth retarded fetuses (IUGR), and 17 healthy control women. Mean AF volume was significantly greater (P < 0.05) in the type-l diabetic group than in the control group. Both concentration and content of AF C-peptide was significantly higher in the type-l diabetic group than in the control group (P < 0.05 and P < 0.01, respectively). The corresponding values were significantly lower in mothers with IUGR fetuses compared to controls (P < 0.05). AF cortisol content was significantly higher (P < 0.05) in the gestational diabetic group compared to the control group; there were no other significant differences between the groups regarding the cortisol concentration or content. Both cortisol and C-peptide contents were significantly interrelated in both control women (r = 0.68, P < 0.01) and women with gestational (r = 0.68, P < 0.05) and type-l diabetes (r = 0.63, P < 0.01). The C-peptide/cortisol ratio was lowest in the IUGR group and highest in the type-l diabetic group. The same ratio was intermediate and almost equal in the control and gestational diabetic group. Both C-peptide and cortisol concentrations were unrelated to AF volume as well as infant birthweight. C-peptide content was significantly correlated to birthweight percentile in type-l diabetic women (r = 0.61, P < 0.05). No such correlation was found in the three other groups.