As any mom can tell you, having a baby takes a big toll. Growing an entire new human being inside your body demands a lot of resources, energy, and time and it can lead to dramatic physiological changes. There’s some evidence that child-bearing benefits longevity, but pregnancy can accelerate biological aging as well. Now, a new review is trying to resolve this tension in the literature.
Two geneticists from Harvard Medical School surveyed data gathered from studies that measured the biological age of women using a variety of methods, including wearable devices, blood tests and epigenetic clocks, and brain imaging. They found that pregnancy seems to speed up the biological clock, but it slows back down postpartum.
Read more: “Pregnancy Changes Perception of Odors and Tastes”
The result of the review is a new framework for thinking about how timing pregnancies affects biological age. “Our previous research has found that biological age transiently rises during pregnancy, peaking around the third trimester or at the time of delivery,” study author Jesse Poganik of Harvard Medical School explained in a statement. “If we accept the idea that these short-term changes in biological age occur, the question is how we can relate those changes to the overall trajectory of aging over the course of a lifetime.”
According to the team, spacing out pregnancies to allow time for the body to recover could be key to healthy aging. Interrupting that recovery interval with another pregnancy, on the other hand, could contribute to accelerated biological aging.
It’s a framework that’s in line with World Health Organization guidelines, which recommend 24 months between pregnancies. However, the team stresses that more research should be conducted before developing any specific protocols for mothers. After all, the end product of the review is a hypothesis, and testing it will require closely following the health of women with multiple births over the course of their lives.
In the end, learning more about birth effects will contribute to a better understanding of aging in general. “There’s a lot of excitement about using biological age-assessment tools to guide individual health on a preventative and personalized level,” Poganik explained. “Studying changes during pregnancy is just one way to gain a more fundamental understanding of aging more broadly.” 
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Lead Image: Nicoleta Ionescu
