Collaborative ECHO research led by Catherine Bulka, PhD, of the University of South Florida, and Rebecca Fry, PhD, of the University of North Carolina at Chapel Hill, investigates whether gene activity in the placenta might differ base on the infant’s sex. The results of this study suggest that the placentas of males and females might develop differently. This research, titled “Sex-based differences in placental DNA methylation profiles related to gestational age: an NIH ECHO meta-analysis,” is published in Epigenetics.
This study included 774 infants (355 female and 419 male) from four ECHO research sites. One of the research sites enrolled infants born at less than 28 weeks, which provided samples from the earliest viable births. Research sites used placental tissue from male and female infants to investigate associations between gestational age (the amount of time the baby spent in-utero) and modifications of placental DNA. Researchers then located the modifications and identified the closest genes, allowing them to analyze the biological significance of the modifications.
The most prominent differences were linked to genes that play significant roles in immunity, inflammation, and pregnancy complications. These differences seen between male and female infants may be important when looking at sex-specific health and developmental outcomes.
“These findings highlight the importance of considering infant sex in studies of the placenta,” said Dr. Bulka. “Doing so may help identify the origins of sex disparities in health and disease that persist throughout life.”
Researchers are now using this data to estimate an infant’s “biological” rather than “chronological” gestational age based on the modification of placental DNA, and the findings of this study suggest that it may be important to consider the infant’s sex when calculating “biological’” gestational age.