A new study has suggested that breastfeeding may have yet another health benefit for women, finding that it could prevent endometriosis.
A chronic and incurable gynecological disorder, endometriosis affects approximately 10 percent of women in the United States, causing chronic pelvic pain, painful periods and pain during intercourse.
The new study, carried out by investigators at Brigham and Women's Hospital, USA, has found that breastfeeding could reduce a woman's chance of developing the sometimes debilitating condition, which up until now has had very few known modifiable risk factors.
The research team used data from the Nurses' Health Study II (NHSII), a prospective cohort study that began in 1989, and follow 72,394 women for more than 20 years.
The team looked at how long each woman breastfed, exclusively breastfed (without the introduction of solid food or formula), and how much time passed before their first postpartum period.
The results showed that women who breastfed for longer periods of time had significantly lower risk of being diagnosed with endometriosis.
For every three additional months that mothers breastfed per pregnancy, they experienced an 8 percent drop in risk of endometriosis, and for mothers who exclusively breastfed the risk dropped by 14 percent.
The team also investigated the effect of breastfeeding throughout the whole of a woman's reproductive lifetime, i.e., breastfeedling more than one child.
This time they found that women who breastfed exclusively for 18 months or more had a nearly 30 percent lower risk of being diagnosed with endometriosis.
To explain the findings, the team investigated the role of postpartum amenorrhea -- the temporary absence of menstrual periods that occurs when a woman is breastfeeding -- however they found that this only explained some of breastfeeding's beneficial effect. Another possible explanation is that breastfeeding changes many of the hormones in a woman's body which have already been found to play a role in endometriosis.
The team concluded that, "Our findings lend support to the body of public health and policy literature that advocates for the promotion of breastfeeding."
"Our work has important implications for advising women who are looking to lower their risk of endometriosis. We hope that future research will illuminate whether breastfeeding could help lessen the symptoms of endometriosis among women who have already been diagnosed."
As part of this research the team are also interested in investigating whether breastfeeding could help ease the symptoms of endometriosis for women who already have been diagnosed with the disease.
The findings can be found published online in the journal BMJ.