Offspring sex determines the impact of the maternal ACE I/D polymorphism on maternal glycaemic control during the last weeks of pregnancy.

Hypothesis/Introduction: We recently demonstrated that fetal sex may affect maternal glycaemic control in genetically prone mothers. We tested the hypothesis that fetal sex/fetal Y/X chromosomes might affect maternal glycaemic control during pregnancy depending on the maternal angiotensin converting enzyme (ACE) I/D polymorphism. Material and methods: One thousand, three hundred and thirty-two Caucasian women without pre-existing diabetes and pre-existing hypertension with singleton pregnancies delivering consecutively at the Charite obstetrics department were genotyped. Glycaemic control was analysed by measuring total glycated haemoglobin at birth. Correction for confounding factors and multiple testing was done. Results: Maternal ACE I/D polymorphism showed significant interaction with fetal sex concerning maternal total glycated haemoglobin. Total glycated haemoglobin in DD mothers delivering boys was 6.42 +/- 0.70% vs. 6.21 +/- 0.66% in DD mother delivering girls (p < 0.005), whereas the II carrying mothers showed the opposite effect. II mothers delivering a girl had a higher (p = 0.044) total glycated haemoglobin at birth (6.40 +/- 0.80%) compared to II mothers delivering boys (6.21 +/- 0.81%). There was no interaction of the ACE I/D polymorphism and fetal sex with respect to new onset proteinuria, new onset edema and pregnancy-induced hypertension. Conclusions: Maternal glycaemic control during the last weeks of pregnancy seems to be influenced by an interaction of the ACE I/D genotyp and fetal sex.