Unexpected vaginal bleeding and COVID-19 vaccination in nonmenstruating women
Altered bleeding pattern after COVID-19 vaccination has been frequently addressed among menstruating women
Menstrual abnormalities after COVID-19 vaccines: A systematic review
A total of 78, 138 vaccinated women
39, 759 (52.05%) had some form of a menstrual problem after vaccination.
22nd September 2023
The Norwegian Institute of Public Health
Association between COVID-19 vaccination and vaginal bleeding,
among nonmenstruating women is not well studied.
Menorrhagia, increased bleeding during period
Metrorrhagia, Irregular bleeds / between menstrual periods.
Polymenorrhea, less than 21 day cycles, therefore more frequent periods
Several cohorts followed throughout the pandemic
Systematic data collection of self-reporting.
Percentages of unexpected vaginal bleeding
(During a period of 8 to 9 months)
50% happened within 28 days of vaccination.
7,725 postmenopausal women, 3.3%
7,148 perimenopausal women, 14.1%
7,052 premenopausal women, 13.1%
In postmenopausal women
The risk of unexpected vaginal bleeding,
in the 4 weeks after vaccination,
was increased two to threefold,
compared to a prevaccination period.
11.1% and 37.5% experienced menstrual symptoms
In nonmenstruating perimenopausal and premenopausal women
Risk of unexpected (breakthrough) vaginal bleeding after vaccination
Increased three to fivefold
In premenopausal women
Spikevax was associated with at 32% increased risk as compared to Comirnaty.
Reports since December 2020,
menstrual disturbances at frequencies not seen in previous vaccination campaigns
Such events were not addressed in the preceding clinical vaccine trials
European Medicines Agency
Recently updated product information of the mRNA vaccines,
to include heavy menstrual bleeding as a potential side effect.
PMB can be a symptom of endometrial carcinoma and precancerous lesions
Women with PMB should be referred for specialized gynecological examination