Pregnancies Linked to a Healthier Heart
In a new study from a single California community, women who had been pregnant at least four times were less likely to die from cardiovascular disease than those who'd never been expecting.
Researchers said that could be due to the protective effects of pregnancy-related hormones as well as the extra social support that comes with having more children — or the fact that women who are able to get pregnant more often are healthier to begin with.
It's not clear that getting pregnant more often protects women's hearts, necessarily.
"It's just one more little piece of the puzzle that maybe physicians should be aware of or think about," said Donna Kritz-Silverstein, from the University of California, San Diego.
"Heart disease is one of the biggest problems facing women today. It's the leading cause of death among women in the United States," Kritz-Silverstein, who worked on the study, told Reuters Health. But, she added, "Many women don't perceive themselves to be at risk."
According to the Centers for Disease Control and Prevention, heart disease kills more than 600,000 Americans a year, about half of them women.
The new study, led by Marni Jacobs at UCSD, involved close to 1,300 women from Rancho Bernardo in Southern California. In the mid-1980s, when participants were in their early 70s, on average, researchers asked them how many times they had been pregnant and given birth. They also surveyed women about lifestyle habits related to heart health, such as smoking and exercise, and measured theircholesterol, blood pressure, height and weight.
For the next 19 years, the researchers brought women in for regular clinic visits, sent them annual questionnaires and used death records to track their diagnoses.
Over that follow-up, 707 women, or about 55 per cent, died of various causes. Just under half of those deaths were due to heart and vascular diseases, including heart failure, heart attacks and strokes.
Compared to women who had never been pregnant, those who reported at least four pregnancies were about 35 per cent less likely to die of any heart or vascular disease, including half as likely to be killed by a stroke or another condition related to artery build-up and high blood pressure. That was after taking into account women's age and weight.
The trend held up when the researchers looked specifically at the number of times women had given birth, and not just how often they'd been pregnant — but in that analysis, they couldn't be sure the lower rates of cardiovascular deaths that came with more kids weren't due to chance.