Older first-time mothers may live longer, study finds.
The Centers for Disease Control and Prevention (CDC) report that the average age of mothers has increased from 24.9 years in 2000 to 26.3 years in 2014.
The proportion of women who became first-time mothers between the ages of 30-34 increased by 28 percent between 2000-2014. First births in women aged 35 years and over also increased by 23 percent in the same period.
According to the CDC, older age in mothers has been linked to a variety of adverse birth outcomes, such as multiple births and congenital disabilities.
But emerging research suggests being an older first-time mother might also have a positive effect, as it may increase the mother's lifespan.
Older first-time mothers may live longer
Researchers from the University of California-San Diego School of Medicine examined for the first time the relationship between longevity and the woman's age at first birth.
They also considered parity, which is the number of times a woman has been pregnant.
The scientists, led by Aladdin Shadyab, Ph.D., examined 20,000 women who were part of the Women's Health Initiative, a national longitudinal study that started in 1991 and examined women all the way through 2012.
Of the 20,000 women included in the study, 54 percent lived to be 90 years old.
Researchers found that mothers who had their first child when they were 25 years or older were more likely to survive to age 90.
They also found that women who lived to 90 years old were more likely to be college graduates, married, and have a higher income. They were also less likely to have obesity or a history of chronic disease.
Shadyab also explains the connection they found with parity, noting that "women with two to four term pregnancies compared with a single term pregnancy were also more likely to live at least 9 decades."
The results of the study were published in the American Journal of Public Health.
Further research needed to explain the findings
"Our findings do not suggest that women should delay having a child, as the risk of obstetric complications, including gestational diabetes and hypertension, is higher with older maternal ages," says Shadyab.
Advanced maternal age has also been linked to an increased risk of stillbirth, preterm births, and fetal macrosomia, which is a condition where the baby is extremely large at birth.
Shadyab also notes the limitations of the study, which is observational and therefore cannot explain causality.
"It is possible that surviving a pregnancy at an older age may be an indicator of good overall health, and as a result, a higher likelihood of longevity," says Shadyab. "It is also possible that women who were older when they had their first child were of a higher social and economic status, and therefore, were more likely to live longer."
Shadyab points out that further research is needed to explain why the age of mothers at first childbirth is proportionally associated with longevity.
"Our findings have several public health implications. We hope this is a foundation to help identify targets for future interventions among women in the preconception and family planning phases of their lives, which may improve women's healthy longevity in the long term."