A longer duration of breast-feeding is associated with a lower risk for endometriosis in the mother, according to a study in The BMJ.
Researchers
studied 72,000 participants from the Nurses' Health Study II who
reported at least one pregnancy. Over 20 years' follow-up, 5% had
confirmed endometriosis.
For every 3 additional months of
total breast-feeding (up to 45 months), the risk for endometriosis fell
by 3%. Women who breast-fed exclusively for 18 months or more across
their reproductive lives had a 27% lower risk than women who didn't
breast-feed exclusively (199 vs. 413 cases per 100,000 person-years).
The association was influenced by longer duration of postpartum
amenorrhea. The authors note that breast-feeding promotes circulating
oxytocin and prolactin and inhibits circulating gonadotropins.
The
authors conclude: "Given the chronic and incurable nature of
endometriosis, breast feeding should be further investigated as an
important modifiable behavior to mitigate risk for pregnant women."
