Postpartum DMPA doesn't prevent lactation. (Pregnancy Prevention).

ASHLAND, ORE. -- Immediate post-partum initiation of progestin-only contraceptives does not appear to interfere with the production of breast milk and protects women against unintended pregnancy in the first months following delivery, Dr. Anita L. Nelson said at the annual meeting of the Pacific Coast Obstetrical and Gynecological Society.

Dr. Nelson and researchers at the Harbor-UCLA Medical Center in Torrance, Calif., studied breast-feeding patterns in 324 new mothers from the time they were discharged from the hospital to 6 weeks postpartum. The rate of breast-feeding continuation was assessed in women who were given injections of depot medroxyprogesterone or progestin-only birth control pills before leaving the hospital, and in women who used nonhormonal forms of birth control during the postpartum period.

The purpose of the study was to explore the validity of a theory suggesting that progesterone withdrawal in the postpartum period triggers lactation. While there are valid reasons to want to provide immediate postpartum contraception, it should not be done at the expense of breast-feeding, Dr. Nelson said. "The benefits of breast-feeding are very important to us," she said, citing child and maternal health benefits and enhanced bonding. "On the other hand, we recognize that many women are at risk for pregnancy."

Spacing a woman's pregnancies has a significant impact on the outcome of the second pregnancy, she said.

Her study was designed around the hypothesis that women receiving progestin-only contraception would discontinue breast-feeding at much higher rates than other women if the volume of their breast milk was lower. If women stopped breast-feeding at the same rates, regardless of contraceptive method, it would suggest that progestin was not ...