Pregnancy can accelerate biological aging in women, a study has found.
Scientists at the Columbia University Mailman School of Public Health in New York looked at the reproductive history and DNA samples of 1,735 people in a long-term, ongoing health survey in the Philippines to investigate the influence of pregnancy on the aging process.
They worked out participants’ biological age using six different “epigenetic clocks” – genetic instruments that estimate biological age based on patterns of a process called DNA methylation.
The study involving 825 young women found that each individual pregnancy a woman reported was linked to an additional two to three months of biological aging, and women who reported being pregnant more often during a six-year follow-up period, has a greater increase in biological aging during that period.
The relationships between pregnancy and biological aging persisted even when the authors controlled for socioeconomic status, smoking, genetic variation, and the built environment in participants’ neighborhoods.
The authors could not find an association between increased biological aging and the number of pregnancies conceived by 910 men of the same age from the same health survey.
The findings are published in the Proceedings of National Academy of Sciences.
Calen Ryan, the lead author of the study and an associate research scientist in the Columbia Aging Center, said: “Our findings suggest that pregnancy accelerates biological aging, and that these effects are evident in young, high-fertility women. Our results is also the first to follow the same women through time, linking changes in each woman’s pregnancy number to changes in her biological age.”
Ryan emphasized the context: “Many of the reported pregnancies in our baseline measure occurred during late adolescence, when women are still growing. We expect this type of pregnancy to be particularly challenging for a growing mother, especially if her access to health care, resources or other forms of support is limited.”
He added: “We still have a lot to learn about the role of pregnancy and other aspects of reproduction in the aging process. We also do not know to what extent accelerated epigenetic aging in these specific individuals will manifest as ill health or mortality decades later in life.”
