A recent study published in the International Journal of Obesity reveals the complex interplay between maternal obesity and genetic ancestry in influencing birth outcomes. Researchers examined data from the NICHD Fetal Growth Studies–Singletons cohort, focusing on 1,810 women across four ancestral reference populations. The study found that maternal pre-pregnancy obesity significantly affects birthweight, placental weight, and the likelihood of infants being born large for gestational age (LGA).
Genetic distance (GD) refers to the measure of genetic divergence between populations within a species. It quantifies how genetically different two populations are, based on variations in their DNA sequences. Populations with many similar alleles have small genetic distances, indicating they are closely related and share a recent common ancestor [1]. In this study, GD from an African reference population was associated with higher birthweight and increased odds of LGA. These associations persisted even after adjusting for socioeconomic status (SES).
Interestingly, the interaction between maternal obesity and GD from Amerindigenous and East Asian references showed varying impacts on placental weight and LGA risk. For instance, the third Amerindigenous GD quintile combined with obesity was linked to a 198-gram increase in placental weight, while the fourth East Asian GD quintile combined with obesity was associated with 86% lower odds of LGA.
These findings underscore the importance of considering both genetic ancestry and maternal obesity in prenatal care. The study suggests that tailored interventions addressing these factors could help minimize adverse pregnancy outcomes. By understanding the nuanced effects of genetic ancestry and obesity, healthcare providers can better support minority communities, ensuring healthier pregnancies and births.
See: “Maternal obesity and ancestry distance in influencing birth outcomes” (April 15, 2025)
