When COVID-19 vaccines first rolled out in the US, an unanticipated side effect emerged. People speculated that the vaccine could have affected the menstrual cycle, NBC News reported. A new study found that 42% of women with a regular period said that they bled more heavily after getting vaccinated.
The study considered the largest, added some support to the claims people were sharing online about COVID-19 vaccines affecting their menstrual cycle.
New Research Sheds Light on How COVID-19 Vaccine Affects Menstrual Cycle
42% of Women Bled More Heavily After COVID-19 Vaccination
Most side effects of the COVID-19 vaccine reported were headaches, fatigue, and soreness in the vaccination site. But another side effect is not well studied and talked about. That is the temporary menstrual change that some women experience.
In the study titled "Investigating trends in those who experience menstrual bleeding changes after SARS-CoV-2 vaccination," published in the journal Science Advances, researchers found that 42% of over 39,000 people with regular menstruation that they surveyed reported bleeding more heavily than usual after vaccination.
Also, around 44% said they experienced no changes, while 14% reported having a lighter period than usual. Some menopausal or non-menstruating people also reported unexpected bleeding after receiving COVID-19 vaccine shots.
The study authors caution that the percentages do not necessarily represent the whole population since people who noticed changes were more likely to participate in the study. They noted that their findings only provide evidence for future studies to establish a causal effect between the vaccine and changes in the menstrual cycle.
The recent study also supports previous studies, such as Dr. Dweck's observations in his January 2022 study published in the journal BMJ, which suggests that those who experienced longer or heavier periods after vaccination returned to their typical flow after two menstrual cycles. Also, a Norwegian study published this year found similar results: periods start to return to normal after two to three cycles.
Few studies have assessed the effect of COVID-19 vaccines on the menstrual cycle and most trials have not included questions about changes in menstruation. The American College of Obstetricians and Gynecologists (ACOG) has already updated their FAQ sheet about the COIVD-19 vaccine and wrote that there might be small changes after vaccination.
ALSO READ: CDC Adds Three New Common Side Effects of COVID-19 Vaccine; Are These Harmful?
Is COVID-19 Vaccine Still Safe Even During Menstruation?
COVID-19 vaccines are safe and the best protection humans have against the SARS-CoV-2 virus and its variants that cause severe and prolonged illness. While some changes in the menstrual cycle may be experienced, the vaccines remain vital as new variants spread throughout the country.
According to an article in Self, more research exploring the interaction between the vaccine and menstruation is needed to fill in the gaps of knowledge on how menstrual cycles respond to the vaccine.
Whereas ACOG has updated its page to include the possible period side effects of the COVID-19 vaccine, the Centers for Disease Control and Prevention (CDC) has yet to update its list of possible side effects from the vaccine to include menstrual changes. Perhaps more information will be collected after further investigation to confirm the link between the two.
RELATED ARTICLE: COVID-19 Vaccine Side Effect: People Report Unusual Menstrual Periods After Injection
Check out more news and information on COVID-19 Vaccines in Science Times.
