Miscarriage, stillbirth, undergoing a hysterectomy, and bearing children at a young age were also associated with elevated odds of cardiovascular problems later in life, researchers found. The additional risk varied from only a few percentage points to more than 40 percent, they reported in the journal Heart.
The findings are not the first to uncover a link between reproductive factors and cardiovascular diseases, and the data do not show a causal relationship, the authors cautioned. But their findings do strengthen the association, and suggest that women with premature reproductive cycles or a history of adverse events should be frequently screened for heart trouble and conditions leading to blood clots.
The scientists drew data from a long-term health survey in Britain that monitored and tested more than a quarter of a million women from 2006 to 2016. The women's average age was 56 when monitoring began. More than four-fifths had been pregnant, and nearly half had two children. On average, they started having their periods at 13, and had their first child at 26.
In 2016, two-thirds of the women had gone through menopause, at an average age of 50. The study showed that women who began menstruating before the age of 12 faced a 10 percent greater risk of cardiovascular disease compared to those who were 13 or older. For those who went through menopause before the age of 47, the risk for cardiovascular disease rose by 33 percent, and for stroke alone by 42 percent.
Miscarriages were likewise linked with a greater danger of heart disease, with each stillbirth increasing the risk by six percent. A hysterectomy was associated with a 20 percent higher chance of developing heart disease, the team found.