A new study in the medical journal Human Reproduction include findings that suggest that women who have had children may age at a more rapid speed than women with no biological children.
This study has nothing to do with raising children so women who adopt or foster children are not, in theory, affected by these findings. This study is only concerned with the aging of women who are biological mothers.
How Much Does Having a Child Ages Women?
According to this new study, having a child could age women up to 11 years. Let us be clear here. When the study talks about “aging”, it is talking about aging on a cellular level, in other words, aging biologically.
Not that this cellular or biological aging would not show to the naked eye. There are some outer signs of cellular aging, most notably the appearance of gray hair.
Having said that, not all the consequence of the accelerated aging that could be caused by having children would be as benign and as easy to deal with as gray hair. Other, more serious consequences of the aging brought by maternity-related aging could include increasing mortality rates and the early onset of age-related health issues.
The reason for this lies in a compound structure known as telomeres. The function of telomeres is to protect your DNA from eventual degeneration. Telomeres are located at the end of chromosomes. But the issue with telomeres is that every time a cell goes through regeneration, the telomeres sitting at the end of the chromosomes become a little shorter. As cell regeneration happens over time, shorter and shorter telomeres indicate aging.
The study does not make it clear why the telomeres become shorter following childbirth, so more research may need to be undertaking.
How Was the Study Conducted?
The authors of this study, A Z Pollack, K Rivers, and K A Ahrens had the following study question: “is telomere length related to parity among a nationally representative sample of US reproductive age women?”
The ultimate answer to this question is that birth is associated with shorter telomere length (and, therefore, possibly accelerated aging).
Before this study was conducted, scientists were aware that there was a link between shorter telomeres and a range of different chronic health conditions and mortality rates. But there was no data linking telomere length with parity (giving birth).
So, this study was conducted nationally in the United States. It included a cross-section of 1954 different women for the National Health and Nutrition Examination Survey, that was conducted in the time period that spans from 1999 to 2002. The reason why this particular survey was chosen by this team of scientists was that this was the only survey period that included the measurement of telomere length, a key element of this study.
The makeup of women included in the study was as follows:
- They were between 20 and 44 years of age.
- They all had to complete a questionnaire including questions on how many previous live births (parity) they had have.
- The study’s participants included nationally representative women in terms of age, race and ethnicity, body mass index (BMI), education, income-to-poverty ration, smoking status, and early age at menarche.
This research project was at least in part funded by the Undergraduate Research Scholars Program at George Mason University.
What Are the Wider Implications of this Study’s Findings?
The main implication of this study’s findings is the suggestion that a history of live birth may be linked to “accelerated cellular aging.”
When compared a history of live birth with other factors that may impact (accelerate) cellular aging such as obesity or smoking, this team has found out that live birth has a higher influence of cellular or biological aging than those others.
What this suggestion means is that more research on shortening telomere is warranted.
But the authors of this study estimate that the telomere shortening caused by live births could be the equivalent of 11 years of aging. In other words, all else being equal (age, ethnicity, smoking status, BMI, etc.), a woman who has had live births could suffer from 11 years’ worth of aging compared to a woman with no biological children of their own.
The fact that live births have a bigger impact than other factors does not mean that those other factors do not have any effect. Women who have had live births and smoke and/or suffer from obesity would age are at an even faster rate. In other words, very often the problem could be caused by the combination of all those different factors. The difference is that thanks to this study, we are now closer to proving that live births are also a factor in the shortening of telomeres and, therefore, cellular or biological aging.
But the authors of this study warned against a caution less interpretation of the results of this study.
In an interview about this study with the New Scientist magazine, Anna Pollack, who is one of the authors of the Human Reproduction paper, says that this should not encourage people and, in particular, women to stop having children.
The heart of a mother is a deep abyss at the bottom of which you will always find forgiveness. – Honore de Blazac
In the same interview, Pollack indicated that other factors that were not looked into in this particular study could also play a part. Because the study was conducted in the United States with participants who had had live births in the United States, the lack of mandatory maternity leave could be a factor. It is important to note here that the United States is the only country in the developed world that does not have mandatory maternity leave (let alone, paternity leave) for new parents.
Pollack herself points out that this could be a factor that generates stress in mothers, which may play a part in cellular aging, too.
At least, now we know that there might be a connection between aging and giving birth. And we also know where future research should look for more answers.