Rosellen Bowen was having a tough time completing her master's thesis. The graduate nursing student was researching whether breast massage would help relieve the pain and discomfort some new mothers experience when they don't breast-feed their babies. But she had trouble finding participants.

During the year she worked on her thesis, over 3,000 babies were born at the University of Rochester Medical School Hospital, where she worked, and the Rochester Community Hospital. But out of the 800 women at these two hospitals who didn't breast-feed their babies, Bowen could only find 46 who said they felt pain when their breasts filled up with milk.

Determining pain is subjective, experts say. But on a 10-point pain scale that Bowen provided for the participants, no mother, at any time, scored pain above a 6.

"She had a lot of trouble completing her thesis with a valid number of patients because [pain] was not a common complaint," says Ruth Lawrence, M.D., a pediatrician who worked with Bowen.

Bowen found that although breast massage did help some new mothers, for most, the long-standing traditional treatment of pain relievers, ice packs, and a well-fitting bra or specially made breast binder was sufficient.

Because other studies have also shown that these traditional treatments provide enough help for the minority of women who do experience pain, and because the drugs used to suppress lactation carry risks, the Food and Drug Administration's Fertility and Maternal Health Drugs Advisory Committee recently recommended that drugs to prevent milk production not be used. Following the committee's recommendation, FDA has asked the manufacturers of these drugs to stop including lactation suppression as an approved use.

The major drug used for suppressing lactation is a non-hormonal substance called bromocriptine. It is also used to treat Parkinson's disease, but because this is a serious disease, the risks associated with the drug's use do not outweigh its benefits. The other lactation-suppressing products all contain the female sex hormone estrogen, alone or in combination with the hormone testosterone. Sending a Message

Even when a woman knows long before her baby is born that she isn't going to breast-feed, her body needs a few non-breast-feeding days after the baby is born to get the message.

In the meantime, milk production begins. First, levels of the hormones estrogen and progesterone, which are very high during pregnancy, drop abruptly after birth. This drop signals another hormone, prolactin, to stimulate milk production in the breast. The milk is produced in cells throughout the breast and then travels through the milk ducts to the openings in the nipple. In a mother who breast-feeds, her baby's suckling signals the prolactin to keep the milk coming. But when a woman doesn't breast-feed her baby, the prolactin levels drop, and milk production ceases.

In the few days it takes before lactation stops, the mother's breasts can fill up with milk. For some non-nursing women, this engorgement is uncomfortable, and occasionally even painful.

Lactation suppression drugs prevent engorgement and, in fact, prevent lactation before it begins. The most commonly prescribed drug, bromocriptine, acts by cutting the production of prolactin. In contrast, the sex hormones keep the estrogen at pre-birth levels, tricking the body into thinking it is still pregnant.

Do They Work?

The National Academy of Sciences/National Research Council (NAS/NRC) reviewed the effectiveness of estrogens and androgens such as testosterone as lactation suppressants approximately 20 years ago as part of a review of all drugs approved before the 1962 drug amendments. (The amendments required, for the first time, that drugs must be effective as well as safe.)

NAS/NRC explained that it did not know of any satisfactory evidence that these drugs could effectively prevent lactation. …