Women who conceived during their teen years and who gave birth to the child are at greater risks for heart and blood vessel disease later in life compared to women who became mothers in the later years.
The research team found that women reporting a first birth before the age of 20 scored significantly higher on Framingham Risk Score, a measure commonly used to estimate the 10-year cardiovascular risk. In comparison, women whose first births occurred at older ages had lower average risk scores: The lowest cardiovascular risk, however, was among women who had never given birth.
"Adolescent mothers may need to be more careful about lifestyle factors that increase the risk of cardiovascular disease, including maintaining a healthy body weight and sufficient physical activity," said study lead author Catherine Pirkle, Ph.D., assistant professor in the Office of Public Health Studies at the University of Hawaii at Manoa in Honolulu.
While previous studies found that women who had several pregnancies had higher cardiovascular risks, here, among women who had children, the number of lifetimes births did not affect cardiovascular risk.
Pirkle notes that women who had never given birth may have miscarried or terminated pregnancies, but would have experienced dramatically lower average levels of pregnancy-related complications. Therefore, they would have no, or much shorter durations, of pregnancy-related stress on the body, which may explain the lower average risk scores in that group.
Investigators obtained information about age at first birth for 1,047 women participating in the International Mobility in Aging Study in 2012. Study participants were between the ages of 65 and 74 and were from Canada, Albania, Colombia and Brazil. Using the Framingham Risk Score, the investigators connected age at first birth to risk for cardiovascular disease.
The findings must be confirmed because this study relied on self-reports of childbirth history which could be affected by memory loss in this older population even though participants were screened for dementia. In addition, many young mothers from the poorer countries may not have survived to the ages of 64-75 years represented in the study, limiting the strength of the findings.
"If adolescent childbirth increases the risk of cardiovascular disease risk, then our findings reinforce the need to assure that girls and adolescents have sufficient sexual education and access to contraception to avoid adolescent childbearing in the first place," Pirkle said.
"If the association is mediated by lower educational attainment, poorer health behaviors and other factors caused by young motherhood, then our findings also suggest a need to provide more support to young mothers."