A study that followed thousands of women for more than 20 years has found that breast-feeding is linked to a lower risk of being diagnosed with endometriosis.
The study, led by Brigham and Women’s Hospital (BWH) in Boston, MA, and published in the BMJ, uses data from the Nurses’ Health Study II (NHSII), which began in 1989.
Corresponding author Dr. Leslie Farland, a research scientist at BWH’s Center for Infertility and Reproductive Surgery, says, “We found that women who breast-fed for a greater duration were less likely to be diagnosed with endometriosis.”
Endometriosis is a chronic, incurable, and often debilitating gynecologic disorder that affects girls and women. It is diagnosed in around 10 percent of women in the United States, note the authors.
The disorder arises when tissue that is similar to the lining of the uterus, or the endometrium, is found attached to other areas in the body, generally in the pelvic cavity. As a result, most women with endometriosis experience “chronic pelvic pain, painful periods, and pain during intercourse.”
Effects of breast-feeding
Dr. Farland and colleagues say that there is growing evidence that breast-feeding brings lasting health benefits to women, such as helping them to lose excess weight and reduce their risk of breast cancer, ovarian cancer, and other chronic diseases.
It has been suggested that breast-feeding has this effect because it prolongs the temporary absence of menstrual periods (postpartum amenorrhea) and because it alters levels of some hormones that are thought to play a role in endometriosis, such as oxytocin, estrogen, and gonadotropin-releasing hormone.