ESPE Abstracts

Introduction: Gestational diabetes mellitus (GDM) is often accompanied by gut dysbiosis, which typically includes a decrease in short chain fatty acid (SCFA)-producing genera. Maternal SCFAs have been found to influence placental immunometabolism and fetal development. The aims of this study were: a) to investigate the associations between maternal and fetal (cord blood-umbilical artery) SCFA levels and offspring anthropometry during the first year of life in pregnancies with GDM, and b) to assess whether the impact of these associations is sex-dependent.

Methods: In this prospective secondary analysis of the MySweetheart study, we included 193 women with GDM and their offspring. Maternal and fetal (n = 39) predictors consisted of serum levels of SCFA including Acetate, Propionate, Butyrate and Crotonic acid at 24-32 weeks of gestational age (GA) and in the cord blood. Offspring outcomes were weight and height z-scores, body mass Index (BMI), small and large for gestational age (SGA, LGA) at birth, as well as weight, height and BMI z-scores at 6-8 weeks and 1 year. Associations were adjusted for maternal age, pre-pregnancy BMI, breastfeeding status (yes/no), and infant age and sex where appropriate.

Results: Mean maternal pre-pregnancy was BMI 25.9 ± 5.6 kg/m². Mean GA at the 1^st GDM visit was 29 ± 2.4 weeks. GA at delivery was 39.7 ± 1.1 weeks, with a mean weight z-score of 0.18 ± 1.1 SD; 11.8% of offspring were LGA. At 6-8 weeks, and 1 year of age, mean offspring BMI z-score was -0.20 ± 1.3 SD, and 0.23 ± 1.1SD. Maternal and fetal SCFA levels were not significantly correlated. In multivariate analyses, maternal 3^rd trimester crotonic acid and cord blood proprionate were positively associated with LGA and length z-score at birth respectively. Maternal 3^rd trimester acetate and cord blood crotonic acid were inversely associated with offspring length and BMI z-score at 6-8 weeks of age respectively. Sex stratified analyses showed differential results, with associations between maternal and cord blood SCFA being observed exclusively in boys, both at 6-8 weeks and 1 year (p ≤0.043).

Conclusion: Our data suggest that maternal and fetal SCFAs may play a role in determining fetal growth in both female and male offspring, whereas their impact on 1^st year growth trajectories seems to be more relevant in male offspring.