COVID-19 vaccine found to affect some women’s menstrual cycle

COVID-19 vaccines were found to affect about 42% of women’s menstrual cycles, a recent study show.

More than 39,000 women were surveyed for the study by researchers at University of Illinois at Urbana-Champaign and Washington University School of Medicine in St. Louis after receiving two vaccines.

The study found 42% of women with regular menstrual cycles bled more heavily during their period after having the vaccinations than they had previously and approximately 44% reported no change after being vaccinated.

Local doctors told this newspaper this was likely a normal inflammatory response following the body’s immune response, and they encouraged individuals to continue to get vaccinated.

“We definitely have seen that in our own patient population in Dayton,” said Kettering Health’s Dr. Shannon McAfee, an OB/GYN.

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McAfee said she had some patients come in who reported they had either two periods in a month or heavy periods after either getting the COVID-19 infection itself or the vaccine. Those changes didn’t last any longer than one to three months, she said.

McAfee said the changes in menstrual cycles were likely another system inflammatory response to the build up of antibodies following the vaccine, like when people experienced other inflammatory responses, like a fever, after getting vaccinated.

“It’s not that the vaccine is impacting the uterus in any way,” McAfee said.

The researchers of the survey also found those who reported experiencing increased or breakthrough bleeding were associated with age and ethnicity, also experienced systemic vaccine effects like fever and/or fatigue, and had a history of pregnancy or birth. Those who were older in the premenopausal respondents, and/or individuals who were Hispanic or Latinx, were more likely to have had heavier bleeding after the vaccines.

“It’s a short-term response,” McAfee said. “It’s not anything that would affect their health in the future.”

The researchers noted that, generally, changes to menstrual bleeding aren’t uncommon or dangerous, but recognizing these experiences can build trust in medicine.

Premier Health’s Dr. Andre Harris, an OB/GYN and the chief medical officer at Atrium Medical Center, explained doctors have seen this type of response in temporary changes to menstrual cycles from other vaccines, like the hepatitis B vaccine.

Additionally, other factors may influence menstrual cycles like with women and gender-diverse individuals who have a lower body fat. Harris used the example of women who are long-distance runners with a thin frame, saying that activity may push their cycle off for several years. Stress can also cause disruptions to an individual’s menstrual cycle.

“Overall, this was short lived,” Harris said.

Harris also cited a study published in January 2022 in the journal Obstetrics & Gynecology, which also supported women’s anecdotal reports of disruptions to their menstrual cycles following getting COVID-19 vaccinations. The study also stated that changes in a menstrual cycle appeared common but temporary following a vaccination.

“There were no long-term effects on a women’s cycle,” Harris said.

The study published last week in Science Advances additionally notes how the instances of breakthrough bleeding for people who are on long-acting reversible contraceptives, who are taking gender-affirming hormones, or who are postmenopausal may have caused some distress for those individuals. Those who experience gender dysphoria with menstruation may have experienced some psychological distress, and postmenopausal individuals may have had concerns regarding whether the breakthrough bleeding was a sign of something worse.

Breakthrough bleeding can be a sign of cancer or pre-cancer for postmenopausal women, and McAfee said she had some patients where they had to rule out those concerns before they could say it was likely just the vaccine causing those temporary issues.

Doctors continue to encourage vaccinations, and health providers said they were happy to conduct consultations with individuals who were hesitant to get vaccinated.

“If you aren’t vaccinated, get vaccinated,” Harris said.

While some of the more recent COVID-19 variants appear to be not as severe as previous variants, pregnant women fall into the category of individuals who are at high-risk of getting a severe illness from COVID. Doctors noted there have been a number of studies to support the safety of the vaccines for pregnant individuals.

“We still recommend our pregnant patients to get vaccinated,” McAfee said.

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