Review article in JDOHaD
/In our systematic review, we found some hints, but no clear associations between gestational weight gain, gestational diabetes and epigenetic alterations in the mother's blood
Observational evidence suggests that maternal body mass index and gestational weight gain affects both the mother’s and the child’s health. The molecular mechanisms mediating these effects are widely unknown, but epigenetic modifications have been proposed.
We performed a systematic review to summarize the current literature on associations between maternal BMI and GWG and epigenetic marks. We carried out systematic searches in PubMed and EMBASE and manual searches of reference lists.
Reported epigenetic marks associated with maternal BMI and GWG were primarily changes in methylation and miRNAs. The most consistent findings were reported for the relationship between maternal BMI and expression of miRNA Let-7d and miR-210, and for methylation of the gene HIF3A and the miR-210 target gene, BDNF. Some of these epigenetic marks have previously been identified in association with neuronal development and hypoxia.
Our review shows that at present, there is insufficient evidence to conclude about the relationships between mother’s BMI and GWG and their associations to epigenetic modifications in mother and child. We made power-calculations exemplifying the need for large sample sizes to obtain adequate strength in studies of epigenetic modifications with small effect sizes and correction of the P-value to avoid false positive findings.
This paper underlines the need for larger, well-powered and methodologically coordinated studies, in addition to meta-analysis of several cohorts to elucidate the potential important relationships between mothers’ weight and epigenetic differences in the mother and her offspring.
Julia Onsrud Opsahl