Changes in Fetal Epigenetics Found Throughout Pregnancy

Researchers at Mount Sinai School of Medicine have found that epigenetic marks on human placentas change from the first trimester of pregnancy to the third, a discovery that may allow clinicians to prevent complications in pregnancy. The finding marks a dramatic departure from the prevailing opinion that epigenetic programming is permanently established 12 weeks after fertilization. Published in the April issue of the American Journal of Obstetrics and Gynecology, the study indicates that clinicians may be able to change the course of a pregnancy through early diagnosis and treatment.

According to the researchers, "We have developed an assay that can allow clinicians to diagnose problems early enough to potentially prevent conditions such as preeclampsia and fetal growth restriction."

Epigenetics generally refers to factors that modify how a gene behaves while not altering the DNA nucleotide sequence of the gene itself. The placenta contains a group of genes, known as "imprinted" genes, which regulate fetal growth. In healthy fetal development, one copy of these genes is normally active and the other copy is silent. Loss of imprinting (LOI) occurs when both sets of genes are reactivated, and is an indicator of potential complications such as preeclampsia and fetal growth restriction.

The surprising results showed that more loss of imprinting occurred in the first trimester than at full term. Dr. Lee and her team concluded that genomic imprinting appears to be an ever-changing process in the placenta, meaning that pregnancy risks can change throughout the course of gestation.

Bonnie - this is exciting research and shows that one needs to be vigilant about lifestyle choices from pre-fertility through birth to ensure the healthiest baby possible.