Covid vaccines and pregnancy. Misinformation about COVID-19 vaccinations has been rampant from the first days vaccines became available—including claims that the vaccines can harm a pregnancy. But researchers at the Yale School of Medicine have found no evidence that the vaccines are associated with difficulties in becoming pregnant, or with birth defects or growth problems.

Ethical concerns limit testing in pregnant people, so the researchers instead injected pregnant mice with high doses of COVID-19 mRNA (messenger RNA) vaccines. They tracked fetal development and found that the mouse babies were born healthy, at normal size, and with no abnormalities.

What about the claims that COVID-19 vaccines stimulate higher levels of antibodies—antibodies that could attack a human protein (syncytin-1) critical for developing the placenta? Good news: the researchers studied blood samples from vaccinated and unvaccinated women and found similar antibody levels in both groups.  
Heart attack risks to younger women. Past research has shown that women under 55 are twice as likely to die after a heart attack—acute myocardial infarction, or AMI—than similarly aged men. Now, a Yale-led study has uncovered significant sex differences in risk factors for AMI. Seven factors were associated with a greater AMI risk in women. From highest to lowest, they are: diabetes, current smoking, depression, hypertension, low household income, family history of AMI, and high cholesterol. Among men, however, current smoking and family history of AMI were the leading risk factors. Senior author Harlan M. Krumholz ’80, professor of medicine and director of the Center for Outcomes Research and Evaluation, notes: “This study speaks to the importance of studying young women suffering heart attacks, a group that has generally been neglected and yet is about as large as the number of young women diagnosed with breast cancer.”

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