45% of Women Report Postvaccine Menstrual Cycle Changes: Journal of Family and Community Medicine

Most common changes are increased menstrual pain (68%) and lengthened cycle duration (52%).

A new study published in the Journal of Family and Community Medicine explores the prevalence of menstrual cycle disturbances following COVID-19 vaccination.

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The study authors looked at 406 women of reproductive age who completed an online survey about postvaccine changes in their menstruation, including cycle duration, bleeding days, and bleeding amount.

Patient characteristics:

• Most of the study participants (≥70%) were 15–25 years old and “single.”

• 53.6% of participants had a history of COVID-19 infection.

• Of the COVID-19 positive women, 73% of the women had mild symptoms (fever, cough, sore throat, malaise, headache, muscle ache, nausea, vomiting, diarrhea, and loss of taste and smell), and 2% had severe symptoms (use of an oxygen machine or admission to hospital).

• 83% of women had received three doses of the vaccine.

• Most women (64.8%) received Pfizer-BioNTech only, followed by 29.8% of women who received mixed (more than one type) vaccines.

• About half of the participants (49%) admitted postvaccine changes in their menstrual cycle.

Of those 406 women, 45% reported postvaccine changes in their menstrual cycle, the study confirms.

The most common menstrual change was increased painful menstrual periods (68%), followed by an increase in the length of the cycle (52%).

Forty-seven percent and 43% of the women noticed menstrual cycle changes after third and second doses, respectively.

The majority (59%) of patients are “still experiencing menstrual disturbances.”

The authors’ affiliations include:

• Department of Physiology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.

• College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.

• College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.

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The new findings corroborate a study published in December in the peer-reviewed journal Cureus that confirmed 41% of women experience menstrual disruptions after receiving a COVID-19 vaccine.

That number increases to 44.1% after a second dose, according to the study.

“The study found that 41.7% (223) of women experienced menstrual changes after the first dose of the COVID-19 vaccine, increasing to 44.1% (236) after the second dose,” it reads.

Significantly, these women had “no history of menstrual irregularities before receiving” a coronavirus jab.

Moreover, an April 2022 study published in The Gazette of Medical Sciences confirmed the “unprecedented rise” in dysmenorrhea (painful menstrual periods) that occurred in 2021, following the distribution of COVID shots.

That study emphasized how decidual cast shedding (DCS)—also known as membranous dysmenorrhea, a gynecological event during which the mucus lining of the uterus is shed in one large piece—is a rare event.

Over the last 109 years, less than 40 DCS cases have been reported in the medical literature.

However, in 2021 alone, 292 women reported having experienced DCS.

The study authors also noted that Google search terms for “decidual cast shedding” substantially increased during the months of April, May, and June 2021.

“These peaks in searches represented a 2000% increase over the first quarter of 2021,” the study authors explained.