NEW YORK (AP) -- A puzzling study of U.S. pregnancies found that women who had miscarriages between 2010 and 2012 were more likely to have had back-to-back annual flu shots that included protection against swine flu.
The study, published Wednesday in the journal Vaccine, found that 17 of 485 miscarriages they studied involved women who miscarried within 28 days of getting a shot that included protection against swine flu, and had a flu shot the previous season. Four of a comparable 485 healthy pregnancies involved women who were vaccinated that way.
Vaccine experts think the results may reflect the older age and other miscarriage risks for the women, and not the flu shots. The government recommends all pregnant women be vaccinated against the flu. Other studies have found flu vaccines are safe during pregnancy.