Maternal and fetal placental growth hormone and IGF axis in type 1 diabetic pregnancy

Aim: Placental growth hormone (PGH) is a major growth hormone in pregnancy and acts with Insulin Like Growth Factor I(IGF-I) and Insulin Like Growth Hormone Binding Protein 3 (IGFBP3). The aim of this study was to investigate PGH, IGF-I andIGFBP3 in non-diabetic (ND) compared to Type 1 Diabetic (T1DM) pregnancies.Methods: This is a prospective study. Maternal samples were obtained from 25 ND and 25 T1DM mothers at 36 weeksgestation. Cord blood was obtained after delivery. PGH, IGF-I and IGFBP3 were measured using ELISA.Results: There was no difference in delivery type, gender of infants or birth weight between groups. In T1DM, maternal PGHsignificantly correlated with ultrasound estimated fetal weight (r = 0.4, p = 0.02), birth weight (r = 0.51, p,0.05) and birthweight centile (r = 0.41, p = 0.03) PGH did not correlate with HbA1c. Maternal IGF-I was lower in T1DM (p = 0.03). Maternaland fetal serum IGFBP3 was higher in T1DM. Maternal third trimester T1DM serum had a significant band at 16 kD onwestern blot, which was not present in ND.Conclusion: Maternal T1DM PGH correlated with both antenatal fetal weight and birth weight, suggesting a significant rolefor PGH in growth in diabetic pregnancy. IGFBP3 is significantly increased in maternal and fetal serum in T1DMpregnancies compared to ND controls, which was explained by increased proteolysis in maternal but not fetal serum. Theseresults suggest that the normal PGH-IGF-I-IGFBP3 axis in pregnancy is abnormal in T1DM pregnancies, which are at higherrisk of macrosomia