A study of nearly 22,000 nonmenstruating, menopausal women found that the risk of unexpected vaginal bleeding increased by as much as five times within four weeks after getting a COVID shot, depending on what stage of menopause the women were in.
In a group of 7,148 perimenopausal and 7,052 premenopausal women, the risk increased by three to five times; in a group of 7,725 postmenopausal women, the risk was two to threefold as compared to prevaccination.
Since unexpected bleeding was not part of the side effects collected in preclinical trials, researchers decided that the product information “should be updated to include heavy menstrual bleeding as a potential side effect.”
Keeping track of unexpected postmenopausal bleeding (PMB) after the COVID shot is important, researchers said, because “PMB can be a symptom of endometrial carcinoma and precancerous lesions and is considered an important medical event” that requires further gynecological care.
SOURCE:
Science Advances September 22, 2023