Women Born in the Spring and Summer More Likely to Die From Heart Disease, Study Suggests

Women born in the summer and spring could have a higher chance of dying of heart disease compared to those born in the autumn, a study suggests.

Researchers examined data on 116,911 women nurses, collected between 1976 and 2014. Out of the total participants, 8,360 died due to cardiovascular disease. When they enrolled in the study, the women were aged between 30 and 55 years old.

The team found a "slight but significant increase" in cardiovascular deaths in women born between March and July. But they didn't discover a link between the season of birth and the overall risk of dying prematurely. The findings were published in the journal The BMJ. More research is needed to confirm the findings and explain the mechanisms underlying the link, the authors said.

Past studies in the U.S., Sweden, Germany, Austria, Denmark, Australia, Lithuania, Japan and Spain, have similarly found a link between the seasons and the month a person was born and their overall risk of dying prematurely, as well as from cardiovascular disease. Research focusing on the northern hemisphere "relatively consistently" found that November babies have the lowest risk of dying of heart disease, as well as overall mortality.

Evidence suggests the month someone is born could affect the types of food mothers eat and which babies consume in early life, as well as potential infections, levels of air pollution, and exposure to sunlight affecting maternal vitamin D levels. But the authors said these studies were unable to adequately show other factors weren't at play.

Limitations of this latest study include the fact that the participants weren't a random sample of people but health professionals, meaning the results might not relate to other populations. Some minority groups in the U.S. were also underrepresented in the data.

"Our study adds to the growing evidence suggesting that individuals born in the spring and summer have higher cardiovascular mortality than those born in autumn, but conflicts with previous findings on overall mortality," the authors wrote.

Heart disease is the number-one killer of women in the U.S. To raise awareness of the fact, the American Heart Association runs the Go Red for Women campaign. According to the organization, heart attack symptoms in women can be less dramatic than men's.

Dr. Nieca Goldberg, medical director for the Joan H. Tisch Center for Women's Health at NYU's Langone Medical Center and an American Heart Association volunteer, said in a statement: "Although men and women can experience chest pressure that feels like an elephant sitting across the chest, women can experience a heart attack without chest pressure.

"Instead they may experience shortness of breath, pressure or pain in the lower chest or upper abdomen, dizziness, lightheadedness or fainting, upper back pressure or extreme fatigue."