The question of whether a menstrual cup can cause a miscarriage is a common concern for individuals who use these products and are trying to conceive or suspect they may be pregnant. There is no medical or anatomical evidence to suggest that using a menstrual cup can cause a miscarriage. A miscarriage, defined as the loss of a pregnancy before 20 weeks, is overwhelmingly the result of biological factors. This lack of connection is grounded in the distinct anatomy of the reproductive system and the established causes of early pregnancy loss.
Physical Separation: Where the Menstrual Cup Sits
A menstrual cup is designed to sit low within the vaginal canal, collecting fluid below the cervix. The cervix physically separates the vagina from the uterus, where a pregnancy develops. The cup rests against the vaginal walls and does not enter the uterine cavity. During pregnancy, the cervix becomes plugged with thick mucus, sealing the uterus and protecting the developing embryo. The cup cannot exert pressure or cause trauma to the gestational sac, as its function is entirely external to the site of the developing pregnancy.
Primary Biological Causes of Miscarriage
The vast majority of miscarriages, particularly those occurring in the first trimester, are due to factors entirely unrelated to external devices like menstrual cups. Chromosomal abnormalities are the single most common cause, accounting for an estimated 50% to 65% of all miscarriages. These losses occur when the embryo cannot develop normally due to an incorrect number of chromosomes or errors in cell division after fertilization. Miscarriage can also be linked to maternal health conditions, such as uncontrolled diabetes, severe kidney disease, or thyroid disorders. Other recognized biological causes include structural problems in the uterus, hormonal imbalances, and specific infections like rubella or listeria.
When to Discontinue Use and Seek Advice
While a menstrual cup cannot cause a miscarriage, it is recommended that a person immediately discontinue its use if pregnancy is suspected or confirmed. The primary reason for this caution is the potential risk of infection. Any internal product, including a menstrual cup or tampon, should be avoided during pregnancy-related bleeding or spotting. Using an inserted product during bleeding carries a theoretical risk of introducing bacteria into the upper reproductive tract. If a user experiences bleeding or pain, they should contact a healthcare provider promptly for guidance and to confirm the source of the bleeding.