A recent study from the Columbia University Mailman School of Public Health suggests that pregnancy may have a negative impact on a woman’s biological age. The study, which involved 1735 young people in the Philippines, found that women who had been pregnant appeared to be biologically older than those who had never been pregnant. Additionally, women who had multiple pregnancies seemed to show even greater signs of biological aging compared to those with fewer pregnancies.The study found that women who had more pregnancies appeared to age biologically faster than those who had fewer pregnancies. Interestingly, there was no link between the number of pregnancies fathered and biological aging in men of the same age, suggesting that pregnancy or breastfeeding specifically may be the factors that accelerate biological aging. These findings were reported in The Proceedings of National Academy of Sciences.
This study expands on previous epidemiological research showing that high fertility can have negative impacts on women’s health and longevity. It was previously unknown whether the costs of reproduction were evident at an earlier stage.In the past, it has been difficult to measure biological aging in young people before they start to experience illness and age-related decline. However, this challenge has been addressed with the development of new tools that use DNA methylation (DNAm) to examine various aspects of cellular aging, health, and mortality risk. These tools, known as ‘epigenetic clocks,’ now allow researchers to study aging at an earlier stage in life, filling an important gap in the study of biological aging.
“Epigenetic clocks have transformed the way we investigate biological aging throughout the lifespan and present new opportunities to examine the long-term health consequences of different lifestyles.Calen Ryan PhD, the lead author of the study and associate research scientist in the Columbia Aging Center, stated that “Our findings suggest that pregnancy speeds up biological aging, and that these effects are apparent in young, high-fertility women.” The study found that the relationship between pregnancy history and biological age persisted even after taking into account various other factors tied to biological aging, such as socioeconomic status. The results also showed that these effects are the first to follow the same women through time, linking changes in each woman’s pregnancy number to changes in her biological age.The study found that women who had experienced pregnancy during late adolescence showed signs of biological aging at a faster rate than those who had not. This was consistent across various measures such as telomere length, epigenetic age, and genetic variation. However, these effects were not observed in men from the same sample. Lead researcher Ryan suggested that this indicates that the process of bearing children, rather than sociocultural factors related to early fertility or sexual activity, may be driving this biological aging.
Despite the significance of these findings, Ryan urges readers to consider the context in which the pregnancies occurred. Many of the pregnancies reported in the study’s initial measurements took place during late adolescence, a period of continued physical growth for women. Pregnancy during this time could pose particular challenges for a developing mother, especially if she has limited access to healthcare, resources, or other forms of support.
Ryan admitted that the level of support is restricted.
Furthermore, Ryan recognized that there is still much work to be done. He stated, “We still have much to discover about the impact of pregnancy and other reproductive aspects on the aging process. Additionally, we are unsure of the extent to which the accelerated aging in these individuals will result in poor health or mortality many years later.”
Ryan pointed out that our current knowledge of epigenetic clocks and their ability to predict health and mortality is largely based on North America and Europe, but the aging process may differ in the Philippines and other regions around the world.
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“In the end, I think our research emphasizes the potential long-term effects of pregnancy on women’s well-being, and the importance of supporting new parents, especially young mothers.”
The co-authors include Christopher Kuzawa from Northwestern University, Nanette R. Lee and Delia B. Carba from USC-Office of Population Studies Foundation, Julie L. MacIsaac, David S. Lin, and Parmida Atashzay from the University of British Columbia, Daniel Belsky from Columbia Public Health and Columbia Aging Center, and Michael S. Kobor from the University of British Columbia, Canadian Institute for Advanced Research, Centre for Molecular Medicine and Therapeutics.
The research was funded by the National Institutes of Health R01AG061006; National Science Foundation BCS 1751912; University of British Columbia UBC 60055724.
