How pregnancy and childbirth accelerates aging

Remember how population experts were worried about a population explosion? Well, they aren’t anymore. Infact, falling fertility rates are shrinking populations of countries across the world. They attribute this global trend to women’s increased drive for education and careers coupled with affordable and accessible contraception. The fertility rate in Kenyan women has been declining too. According to the United Nations Population Division World Population Prospects and Kenya’s Census reports, the average Kenyan woman would have 8.126 live births in 1966, 5.4 in 1996 to 3.468 in 2019. Women continue to have fewer babies as years go by. Is this a good thing for women?

The pregnancy glow is temporary

Scientists from the University of Washington caution about the possibility that multiple pregnancies could make a woman age faster. An excerpt from the study published in Scientific Reports states, “Even after accounting for other factors that affect cellular ageing, the number of pregnancies still came out on top.” This conclusion was reached at after analysing two cellular aging markers in young women with dissimilar reproductive histories. Even if pregnancy gives women that beautiful glow, makes them look younger, it is only temporary. Cumulative and lasting effects of the strained body processes show up later in life.

Advanced age is also considered one of the predictors of frailty, illness and mortality. Lifestyle factors that have been linked to accelerated ageing include socioeconomic status, obesity and smoking. Women have been shown to go through extensive changes in anatomy and physiology during pregnancy. Pregnancy and breastfeeding are accompanied by high energy consumption cutting across the entire body’s physiological systems. These energy-costly processes such as changes in immune function, blood pressure and volume, hormone levels, energy metabolism and storage, compound with each subsequent pregnancy. These changes accelerate aging by straining the maintenance and repair of cells.

 Effects felt after menopause

A similar study by Penn State researchers found that the effects of pregnancy-related aging were “only found after a person has gone through menopause.” Why? “Previous research has found that generally, ovarian hormones are protective against some cellular level processes that might accelerate aging. So it is possible that in premenopausal women, the effects of the hormones are buffering the potential negative effect of pregnancy and reproduction and biological age acceleration. And perhaps when the hormones are gone, the effects can show themselves”, notes Talia Shirazi, the principal investigator. Interestingly, minimum age acceleration was observed at 3-4 live births, with each pregnancy aging a mother’s cells by up to two years! The aging was more in those with fewer births or more than four.

The paradox

Isn’t it strange that our grandmothers, some of whom have had more than eight live births, are still doing quite okay? The younger generations could be aging earlier compared to them. It is hypothesised that extensive support structure may help reduce mother’s stress levels and result in such findings. For instance, in the African culture, we grew up seeing relatives showing up to help out with the new-born. This extensive support could explain the discrepancies between research findings in other countries and our very own observations. It is noteworthy that the level of such community support for pregnant women and new mums is diminishing. Lifestyle and diet also played important roles to keep these women active despite having given birth many times. Women with less community support suffer relatively numerous sleepless nights, have a hard time dealing with their baby’s tantrums, or worry endlessly, which can speed up the aging process.

Women with no children

The Penn State study suggests that women with no children or only one child may also experience lower levels of social support, which could have negative consequences on health later on in life.