COVID-19 Vaccines Can Impact Menstrual Cycle, Researchers Find

Researchers confirmed that COVID-19 vaccines are linked to changes in the menstrual cycle, according to a study published in March. Published in the Obstetrics & Gynecology journal on March 1, Oregon Health & Science University researchers found that women who received a COVID-19 shot in the first half of their menstrual cycle are likely to receive cycle length changes than whose who received the vaccine in the second half. Those researchers used data from 20,000 users of a birth control app that was approved by the U.S. Food and Drug Administration (FDA) to determine what effects the vaccine has on the cycle. Most of women whose data was analyzed were under the age of 35, while 28 percent were from North America, 33 percent were from Europe, and another 32 percent were from the United Kingdom, they said....