More specifically, a lot of women have been concerned about how the vaccines affect their reproductive health, fertility and menstrual cycle. According to the results of a large new study, 42% of people with regular menstrual cycles reported heavier bleeding post-vaccination, 44% said they experienced no change, and 14% reported lighter bleeding after vaccination. Researchers observed 39,000 fully vaccinated people from 18 to 80 years old who never had COVID. The study authors explained that it’s important to note that the results are not necessarily an accurate depiction of the population as a whole since the people who experienced menstrual changes were more likely to take part in the study.
What We Can Take Away From this Study
While this study presents some interesting information, there are many additional factors that need to be taken into account. Here’s how experts want you to think about the findings. “There are many extraneous variables that didn’t appear to be considered, like how many women had fibroids, polyps, were stressed, were in early stages of pregnancy, and so on,” says Dr. Kecia Gaither, MD, MPH, MS/MBA, FACOG, double board-certified in OB/GYN at NYC Health + Hospitals/Lincoln in the Bronx. “One has to consider response bias in the case of utilizing surveys for research." She explains that response bias is defined as the tendency of respondents to answer inaccurately or untruthfully, which can occur if participants are asked to self-report on behaviors or occurrences. Navya Mysore MDCM, CCFP, National Program Director, Reproductive & Sexual Health and Family Physician & Tribeca Office Medical Director, explains that this study reinforces what we’ve already seen—COVID vaccines can change the length and quality of your cycle.
What’s the Science Behind the Vaccine Affecting Your Period?
Our body likes routine and homeostasis. When our body shifts for any reason—including the COVID vaccine—this can affect our cycle, Dr. Mysore states. Our endometrium is what sheds during our period, and we know that our endometrium is linked to our immune system. So any shifts in our immune system (like being over-engaged in processing the COVID vaccine) can cause changes to our cycle. Dr. Gaither says that there is currently no physiologic pathway that specifically ties a vaccine to menstrual irregularities. Perhaps one exists, but that is unknown to physicians or researchers—only time will tell. While they seem like they’ve been around forever, both COVID-19 and the COVID vaccine are still very new, and there’s a lot we still need to learn and study.
Yes, You Should Keep an Eye On Your Period—but Don’t Worry
Changes in our period can happen for a handful of reasons, and while this study is a large one, there’s still so much we don’t know. For now, we do know that the COVID vaccines help prevent infection and seriously reduce the chances of people getting severely ill or being hospitalized. For now, medical experts believe the benefits of the vaccine outweigh any risks associated with temporary menstrual cycle changes. “Shifts in our period happen all the time and not just related to the vaccine," Dr. Mysore explains. “Changes in diet, sleep patterns, other illnesses and conditions, jet lag, and so on can all shift our period for a cycle or two but normally always shifts back to your normal pattern.” That being said, if you notice that your period is different for more than one or two cycles, check in with your primary care provider or your OBGYN to make sure that there isn’t something else that could be contributing to these changes. Dr. Gaither also cautions that any irregular vaginal bleeding should prompt a visit to your health provider, particularly among postmenopausal women. Next up: Dealing With Worse Than Usual PMS Symptoms? You’re Not Alone—and There’s a Diet That Can Help
Sources
Science Advances: “Investigating trends in those who experience menstrual bleeding changes after SARS-CoV-2 vaccination”Kecia Gaither, MD, MPH, MS/MBA, FACOG, double board-certified in OB/GYN and Maternal Fetal Medicine, Director of Perinatal Services/Maternal Fetal Medicine at NYC Health + Hospitals/Lincoln in the BronxNavya Mysore MDCM, CCFP, National Program Director, Reproductive & Sexual Health and Family Physician & Tribeca Office Medical Director
