The Number of Kids You Have May Be Connected to Rate of Aging, Study Finds

Some say motherhood keeps you eternally young, while others feel it ages you faster than anything else. A recent small-scale study shows both may be right, depending on the number of kids they’ve had.

A recent study published in the journalScientific Reports shows a bizarre connection between the number of kids a woman has had and how fast she ages after menopause. While mothers everywhere nod their heads in unsurprised agreement, the study actually reported a surprising U-shaped correlation between the two factors.

Study Findings

According to the study, moms of five or more kids showed more advanced age markers than those with two to four. But here’s where things get weird: moms with only one kid (and women with no kids)alsoaged faster than moms who had between two and four kids.

Several different measures of aging were considered in the study and are as follows:

• Homeostatic Dysregulation. A measure of how much a person’s physiology deviates from a young, healthy reference norm.
• Klemera–Doubal Method. A method in which a person’s biological age is based on their chronological age and weight adjusted for select biomarkers.
• Levine Method. A method in which a person’s biological age is interpretable as the chronological age at which their physiology-based risk for mortality would be approximately normal in the reference population.

*descriptions provided by Dr. Kim Langdon, an Ohio-based OB/GYN and contributor forMedzino.

Pregnancy is Tough on the Body

Regardless of the measure used, the study found that women with no children or only one child, along with women with five or more kids, had a higher risk of death from accelerated aging, especially after menopause. “Mortality risk from specific causes including coronary disease, circulatory disease, and cancer were increased for multiparous women,” says Langdon.

It’s hard to deny it: pregnancy is extremely hard on the body, no matter how many times a woman goes through it. “It is a huge biological stress on the cardiovascular system, metabolism, lungs, kidneys, and weight,” says Langdon. “And women who develop pregnancy-related conditions are more likely to continue to deal with those conditions. As an example, women who develop gestational diabetes are more likely to develop overt type II diabetes due to genetics and obesity.”

A U-Shaped Correlation

How can it be explained that biological age acceleration reaches a minimum at two to four live births and begins to increase at the upper and lower extremes? There could be a few explanations, none of which have anything to do with the stress that comes with raising kids.

Langdon says it could be different factors at each end of the spectrum. “Women who have only one birth could have issues with fertility such as PCOS or an underlying serious medical illness such as lupus—which are independent risk factors for cardiovascular disease and death.”

Further, she speculates that perhaps moms with many kids (more than five, per the study findings) may be carrying around more total body fat than women who have given birth to fewer children. “Women who have multiple children are more likely to have not shed their weight from pregnancy, and obesity is a risk factor for mortality. It’s possible many of these women may have less access to health care and birth control...which can increase the risk of mortality.”