A University of Southern California-led team reporting in JAMA Network Open explores potential relationships between pregnancy complications and infants' biological age at birth, estimated with epigenetic gestational clock algorithms. Using array-based DNA methylation profiles, the researchers first estimated the biological age for 1,801 children of diverse ancestry who were born at 30 to 43 weeks chronological age to mothers between the ages of 16 and 45 years old. From there, they incorporated information on maternal pregnancy complications, particularly gestational diabetes, gestational hypertension, or preeclampsia, demonstrating that female babies born to women experiencing gestational diabetes or preeclampsia tended to have lower biological maturity at birth compared with other babies — an effect not found for neonates with prenatal exposure to gestational hypertension. From these and other findings, the authors argue that "it will be important to further understand epigenetic mechanisms potentially at play in fetal programming and the relevance of the intrauterine environment on downstream health outcomes in offspring."