Many people who have been vaccinated with COVID-19 have experienced symptoms such as swollen nodes “COVID arms”, and Blood Clots. Many of us have not experienced these reactions before. Some side effects are related to your body’s response to the vaccination. What about reports of menstrual cycle changes after vaccination?
Evidence that Covid-19 vaccines have a direct impact on menstrual cycle is still developing. Several studies have found a link between vaccines and changes in menstruation. Experts say that these changes are most likely caused by your immune system and shouldn’t be a concern.
George Fyffe MD, FACOG shares his insights on why this could be happening.
Research on COVID-19 Vaccines and Menstruation
Since the COVID-19 vaccines were introduced, there has been a lot of discussion about the link between vaccination and menstruation. Four different studies were published, which sparked a growing interest. Two studies examined the relationship between vaccines and menses (also called periods). Two other studies examined the relationship between vaccines and menstruation.
Menstrual flow and COVID-19 vaccination
Let’s start with menstruation: the period itself.
In April 2022, a study published in Science Advances shared the results of an online survey on menstrual bleeding after COVID-19 vaccine. Out of the 16,000 women who responded to the survey, 42% said they bled more than usual during their period.
People who do not have menstruation, either because they are post-menopausal or on long-term contraceptives, or take hormones that affirm their gender, also report breakthrough bleeding or other unexpected bleeding.
This is a staggering number. This number is also likely to be inaccurate. It’s possible that a woman is more likely to respond if she’s noticed anything unusual in her menstrual cycle.
A study from Norway in January 2022 found that only 13% of respondents reported a higher-than-normal water flow.
These studies were not designed to establish causality between COVID-19 vaccination and menstruation. They however, show that more research is needed into this phenomenon.
Menstrual cycle and COVID-19 vaccination
You might experience a heavier cycle after receiving the COVID-19 vaccination. How about the entire menstrual period? Does the jab also affect this?
Obstetrics & Gynecology published in July 2022 a study which showed that the menstrual cycle length increased after COVID-19 vaccine. A study funded by the National Institutes of Health in September 2022 confirmed this finding.
According to the current research, the vaccination has a very minor impact on the lengthening of the menstrual period, increasing it on average by less than one day. Although we think of a menstrual period as being 28 days long, variations are completely normal. The majority of doctors don’t worry about cycle variations unless they are greater than 8 days.
These findings are observational, just as in the study on COVID-19 and menses. This means that they cannot tell us whythe vaccination is affecting menstrual cycle duration. Doctors already have a theory to explain these findings.
Your immune system and your menstrual cycle
There is a link between the uterus, and your immune system. We may not be aware of it. Dr. Fyffe explains that your immune system increases its activity as you are about to ovulate to protect against anything interfering in the fertilization and implantation process of the egg. Your immune system will then go down once the fertilized egg has implanted. This is to allow you to accept your pregnancy.
According to Dr. Fyffe the lining of the uterus has immune cells. These cells are affected by hormonal fluctuations.
He explains that the Hypothalamus is the center for hormonal control in the brain. It works with the anterior gland pituitary. Together, the pituitary and ovaries send hormones to communicate messages. These messages instruct the ovaries on how to adjust hormone levels in order to promote ovulation or pregnancy, or — if there is no fertilization — to return the menstrual period. These same messages also affect the immune system.
He adds that “emotional stress, chemical stress, and physical stress can all have an impact on the hormonal control centre, which can lead to changes in the menstrual cycle.”
A vaccine is a chemical stress. However, it’s not dangerous. Your period is a sign that your immune system has responded, and this is the purpose of vaccination.
What happens if your period changes after you have been vaccinated against COVID-19?
Most post-vaccination changes are minor, and should not cause alarm. Speak to your doctor if you notice a significant disruption in your cycle, or if your menses have changed significantly. Dr. Fyffe believes that you and your healthcare provider should work together to decide the best course.
Bottom line: COVID-19 vaccines are safe, effective, and vitally essential to our collective well-being. You can wear your sleeves with confidence that any side effects related to periods will be temporary.
