Many of us are aware of the increased risks posed to mother and baby if a woman of advanced maternal age becomes pregnant. For example, previous studies have found pregnant women 35 and older have an increased risk of impaired blood vessel function and reduced blood flow to the placenta.
But new research out of the University of Alberta has added one more risk to the growing list: it suggests that delaying pregnancy may increase the overall risk of cardiovascular disease in both mothers and their male children later in life.
The research, published in The Journal of Physiology, studied rats to determine the outcomes of advanced maternal age and pregnancy. They grouped the rats into three categories: never pregnant, postpartum and pregnancy loss. What they found was that the pregnancy loss group had less vasodilation (widening of the blood vessels) compared to the other two groups. The postpartum group, interestingly, experienced the same impairment in the arteries of the intestines.
"These data demonstrate mechanisms which may lead to worsened outcomes at an advanced maternal age, including early pregnancy termination, and later life cardiovascular dysfunction," the research team said.
When it came to health risks the rats' offspring, researchers found striking differences between the two sexes. Males, for example, had impaired function of the blood vessel lining and cardiac risk factors associated with interrupted blood flow. Females, on the other hand, did not.
Researchers believe that these results could be extremely helpful in providing opportunities to develop preventative treatments for children born to older women.
"Given the increasing trend toward delaying pregnancy, our findings have significant population and healthcare implications and further illustrate pregnancy as a window of opportunity to assess cardiovascular health," they said.
The research team from the University of Alberta presented their findings earlier this month at the American Physiological Society's (APS) Cardiovascular, Renal and Metabolic Diseases: Sex-Specific Implications for Physiology conference in Knoxville, Tennessee.
Interestingly, while heart conditions have been shown to be brought on by pregnancy, recent data has shown that most women with heart disease can still safely carry a child. The data shows that fewer women with heart disease die or have heart failure during pregnancy than ten years ago, and more women with heart conditions are becoming pregnant than ever before.
Experts believe that this is because corrective surgery has vastly improved survival rates, ensuring more women reach reproductive age. In fact, the number of women with conditions considered very high risk by the World Health Organization (WHO) increased from around 1% in 2007 to 10% in 2018.