Scientists say pregnancy can make you age faster

Research suggests pregnancy can accelerate biological age in women at faster rate than those who have never been pregnant

Scientists have found that just one pregnancy can accelerate a mother’s biological age.

In a recent study published in Proceedings of the National Academy of Sciences, scientists have found that women who have already experienced pregnancy were more likely to exhibit signs of accelerated biological ageing as opposed to those who have not been pregnant. Associate research scientist Calen Ryan, who has been studying the long-term effects of pregnancy at the Columbia University Aging Center at the Mailman School of Public Health, explained to Time that pregnancy can lead to an increase in health risks.

“We’re learning that pregnancy has long-term effects on the body,” Ryan told the outlet. “They are not all bad, but it seems to increase the risk of some diseases and all-cause mortality.”

Ryan and his team have theorised that the acceleration in biological ageing primarily occurs because of the great physical toll pregnancy can take on the body. “The idea is that the body performs certain functions, but is always constrained about optimising any one of those functions, and it creates a trade-off,” Ryan noted. “So, energy going toward reproductive function may draw away from maintenance of the body.”

Through data obtained by the Cebu Longitudinal Health and Nutrition Survey, Ryan and his team analysed the blood samples from 1,700 people from the Philippines, each between the ages 20 to 22 when the study began in 2005. The study also asked questions about participants’ reproductive and sexual history, and number of pregnancies - accounting for factors such as pollution and socioeconomic factors, which could affect ageing in both their male and female participants. The team contrasted the results with data collected from a smaller pool of female participants between 2009 and 2014.

In the blood samples, the team looked at factors that could influence or cause accelerated biological ageing, particularly “epigenetic clocks,” which indicate a cell’s age. Over time, cells acquire molecular imprints that indicate which genes have been turned on or off, showing which DNA sequences have been modified. Because epigenetic clocks serve as a snapshot of the changes that have occurred in a cell over time - including effects of external issues such as stress, and physiological and psychological experiences - scientists use them as a metric to identify the biological age of cells.

By using six epigenetic clocks to identify 19 different mutation indicators that gauge a participant’s biological age, the team concluded that women who had been pregnant at least once were biologically older than those who had never been pregnant. The data suggested that biological age increased by three per cent more per year in those who have been pregnant, and those with more than one pregnancy were said to age up to five months faster.

The team contrasted their findings by testing the same six epigenetic clocks in male participants, noting that the men who had welcomed children with their partners experienced no biological ageing as a result of having a child.

However, in a paper published in the scientific journal Cell Metabolism, a research team from the Yale School of Medicine led by Kieran O’Donnell reported they found that rapid acceleration in ageing caused by pregnancy was found to be gradually reversed a few months post-partum.

“The reversal in postpartum in terms of the effect size was much greater than the increase in biological age found during pregnancy,” O’Donnell explained. “That raises the provocative idea that pregnancy may be associated with potential rejuvenation. But we simply can’t answer that question for sure with the data we have so far.”

It’s clear that more research is needed to conclude whether the effects that pregnancy has on biological ageing can be completely reversed post-pregnancy. Scientists are optimistic about the results from the data they’ve acquired, but only time will tell just how much pregnancy can affect women in the long run.