How COVID-19 vaccines can affect periods, new study finds

  • A new study shows that women may experience short-term changes in their menstrual cycles after vaccination against COVID-19.
  • The researchers found that these changes were associated with all types of COVID-19 vaccines. But, experts still recommend that menstruating people get their COVID-19 vaccines.
  • “The good news from the data is that the changes were temporary and short-lived with no long-term consequences.”

Since the first wave of COVID-19 vaccines became available, we have continued to learn more and more about how the vaccine affects our bodies, with most side effects being of little consequence. And while that remains true, a new study suggests that COVID-19 vaccines can affect your period.

Specifically, healthcare professionals have now identified a potential link between COVID-19 vaccination and short-term changes in menstrual cycle length and regularity. The study (the largest to date) was published last week by researchers at the University of Illinois, Urbana-Champaign and its findings have already raised several questions for menstruating people.

In early 2021, many people started sharing that they experienced unexpected menstrual bleeding after receiving their first COVID-19 vaccine. To dig deeper into this phenomenon, the researchers asked 39,129 people who had received a two-dose SARS-CoV-2 vaccination a series of questions about period changes and vaccine experiences.

In this sample, 42% of people with regular menstrual cycles reported bleeding more heavily than usual after being vaccinated, while 44% reported no change. Among respondents who usually do not menstruate, 71% of people on long-acting reversible contraceptives, 39% of people on gender-affirming hormones, and 66% of people in menopause reported breakthrough bleeding.

“The vaccine does not affect your fertility at all.”

The researchers also found that increased bleeding after vaccination was significantly associated with older age, systemic vaccine side effects (fever and/or fatigue), lighter typical menstrual flow, have ever been pregnant or given birth and ethnicity, especially Hispanic/Latinx. . For nonmenstruating premenopausal people, breakthrough bleeding was more likely if they had previously been pregnant and/or had given birth. For people in menopause, breakthrough bleeding was more likely to be Hispanic/Latin. Finally, people with regular periods with endometriosis, menorrhagia, fibroids and PCOS were slightly more likely to have heavier bleeding.

Ultimately, the results of this study demonstrated that respondents in the sample who menstruated regularly were about equally likely to have no change in bleeding after vaccination or to have heavier periods after the vaccination. A much smaller proportion of people had lighter periods. The study pointed out that “generally, changes in menstrual bleeding are not uncommon or dangerous, but paying attention to these experiences is necessary to build confidence in medicine.”

It is also important to note the limitations of this study. Since this study was based solely on participants’ personal responses, the results may have been skewed due to self-report bias. And people who experience menstrual changes are more likely to have responded to the survey. Also, this study did not compare the results with a control group of unvaccinated people.

Kate White, MD, associate professor of OB/GYN at Boston University School of Medicine and author of Your Sexual Health: A Guide to Understanding, Loving and Caring for Your Body, agrees that this study is limited by the web-based design. “Furthermore, a very high percentage of respondents were white, which may not reflect the experiences of all people. But the size of the study (over 39,000 people) is an incredible strength.

Yet these results are consistent with smaller studies that have reported menstrual changes after vaccination while using a control group (unvaccinated people).

What should we take away from these new discoveries?

“Many women noticed changes in their menstrual cycle after receiving the Covid vaccine and their concerns were often brushed aside or told that their cycle was affected by anxiety. This study highlights the fact that women know their bodies better and that the changes were not in their ‘head’, but rather a real side effect of the vaccine,” says Jennifer Wider, MD, women’s health expert. . She adds that “the good news from the data is that the changes were temporary and short-lived with no long-term consequences.”

“There is no long-term impact on your period.”

These new findings will likely affect how healthcare professionals view sequelae of COVID-19 vaccines and further consider menstrual health in trials of other vaccines. Dr Wider says, “This study highlights how important it is for researchers to monitor menstrual health in future vaccine trials and to better understand the underlying biological mechanisms at play.”

Do menstruating people still need to get vaccinated?

The answer is yes. “All people, whether menstruating or not, should get the COVID vaccine,” says Dr. White. “It is important that doctors inform patients that the vaccine may temporarily disrupt their periods, but there is no long-term impact on your periods and the vaccine does not affect your fertility in any way.”

Dr White goes on to say, “COVID-19 continues to be a serious infection for many people, and everyone is at risk of repeated infection with the new variants (although the vaccine still offers protection to the both against any infection and against a serious infection). .so vaccine protection is worth it in the short term with your period.

Given that the menstrual changes seen in study participants were temporary and short-lived, Dr. Wider agrees, saying “the importance of getting vaccinated far outweighs the short-term risk.” to have a change in your menstrual cycle”.

Dr Wider adds that this study “should raise awareness in women who have irregular periods or lighter bleeding cycles that they may experience changes or heavier bleeding and this would likely be caused by the vaccine.” So, ultimately, the study should serve as a potential explanation for heavier menstrual cycles in some, after vaccination.

Can COVID-19 infection also affect menstruation?

According to Dr. Wider, “women who had COVID reported a change in their menstrual cycle.” However, more studies are definitely needed to understand why this may be the case.

“Any infection (or severe stress) can affect your period…and early studies have shown that COVID-19 infection can alter your period in a number of ways,” says Dr. White. “The amount of bleeding you see can change – most often this leads to a lighter period, but some people have a heavier flow. The timing of your bleeding can also change – sometimes your next period comes early, and more often your next period comes late (or not at all) and these disturbances can be present for a long time.

Yet, Dr. Wider points out, despite reports that women with COVID-19 have reported changes in their menstrual cycles, “further studies are definitely needed to understand why this may be the case.”

The bottom line

Getting vaccinated is always important. But he is always a good idea to track your menstrual cycles. And it is especially safe to follow your period after vaccination. But rest assured that if you notice any short-term irregularities in your cycle, there’s no cause for alarm, says Dr. Wider. “If irregular patterns persist, it would be wise to bring it to the attention of a health care provider.

This article is accurate at the time of press. However, as the COVID-19 pandemic rapidly evolves and the scientific community’s understanding of the novel coronavirus grows, some information may have changed since it was last updated. While we aim to keep all of our stories up to date, please visit the online resources provided by the CDC, WHOand your local public health department to stay informed of the latest news. Always consult your physician for professional medical advice.

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