Your patients may have seen news reports or heard stories of friends having an unusually heavy or abnormal menstrual cycle after getting a COVID-19 vaccine. While research has not firmly established a connection between the vaccine and menstrual changes, enough people have reported this side effect that OB-GYNs should be aware and prepared to discuss with patients. Consider the following when interacting with patients who are concerned about the COVID vaccine's effect on menstrual cycles.
Does the COVID Vaccine Affect Menstrual Cycles?
It is possible that future research will reveal new, harmless side effects of the COVID-19 vaccine, such as menstrual disruptions. As with many new therapies or treatments, unexpected side effects begin to appear once more people receive the therapy.
All evidence so far is anecdotal. Heavy periods were not reported during clinical trials, but it is likely that patients were not asked about this side effect. Menstrual changes were reported unofficially by patients who received the mRNA vaccines by Pfizer and Moderna in the U.S., as well as with the AstraZeneca vaccine in the U.K.
Most women who reported this side effect reported a heavy, painful period after their second dose of the vaccine. In most cases, it seems to be just one disrupted cycle.
So far, researchers have not found specific ingredients in the vaccine that could disrupt a menstrual cycle. But OB-GYNs shared some possible explanations for the reports of the COVID vaccine's effect on menstrual cycles in an article for Women's Health magazine:
- Immune response. The reproductive system has a close link to the immune system. The vaccine stimulates a strong immune response, which could affect the uterine lining or endocrine levels. A cold, the flu or another virus could also disrupt the menstrual cycle.
- Stress. The pandemic has, understandably, raised everyone's stress level. Getting a shot, particularly one that uses a newer technology, can be stressful for many people; stress is known to cause abnormal menstruation in some cases. As anecdotes about the vaccine side effects spread, the anticipation and uncertainty may lead to even more stress about getting the shot.
- Age and health. The vaccines were first offered to older women and people with chronic medical conditions. Both populations are more likely to have abnormal bleeding than younger women. Many women have an off cycle every now and then, so it is possible that some cases are coincidences.
Is There Reason to Worry?
So far, it does not seem like anything to worry about. Most women return to normal menstruation within a cycle or two. Women can experience one or two abnormal cycles anytime without cause for concern.
Gynecologists interviewed for HealthyWomen.org shared similar sentiments. So far, the OB-GYN community has not viewed menstrual disruptions as an ongoing problem or a major health concern. One doctor recommended that women who are worried about the vaccine's effects on menstruation could time the second dose at the end of their period to potentially lessen any impact.
How Do You Reassure Patients?
With the current mixed feelings about the COVID-19 vaccine among some in the larger population, you may have patients who worry about possible side effects and bring questions. Reassure patients by discussing the benefits of the vaccine. Acknowledge their concerns and what is known. For example, an off menstrual cycle is possible after the second dose, but there is no evidence to suggest the vaccine causes infertility.
Let patients know what signs to look for when there is an issue that needs further exploration. Repeated abnormal cycles or heavy bleeding can be a sign of endometriosis or fibroids, unrelated to the vaccine.
These are stressful times in uncharted territory for a lot of people. Keep lines of communication open to maintain trust with your patients. Listen to their concerns, provide reassurance and share vetted information about what's known at the time.
