There's currently no clear-cut test for IGT, and some women with very strong signs of it make enough milk. Similarly, surgery-related lactation problems are hard to predict.
So the only way for a woman with risk factors to really know if she has chronic low milk supply is to try breast-feeding with proper technique and pumping, and see if it works.
The process can be emotionally brutal.
"It was the most heartbreaking thing I've ever gone through," says Nichole Pool, 27, of Tehachapi, Calif., whose baby nursed and cried more or less continually for three days, despite help from a lactation consultant. "Here's this tiny little person who literally depends on me and my husband for everything to keep her alive, and I don't understand why she's screaming. I just want to fix it. She wasn't going to the bathroom or anything, and I was just like, 'Is something wrong with her?' I didn't sleep for three days because I just wanted to hold her and make it better."
There are some good lactation consultants, according to Krystal Revai, a fellow of the Academy of Breastfeeding Medicine, but if a woman has chronic low milk supply, she should seek the help of an ABM physician, a doctor with breast-feeding expertise. If you're choosing among lactation consultants, some low milk supply mothers suggest going with one who is board certified and more likely to be up-to-date in her knowledge.
Herbs such as fenugreek and the medications metoclopramide (Reglan) and domperidone are sometimes used to boost milk supply, but evidence that they work generally comes from poor-quality studies, according to the ABM. Reglan's potential side effects include depression, and domperidone is not FDA-approved in the U.S. Herbs have allergic potential and may harbor contaminants.
Some women with low milk supply switch to formula feeding, saying that grueling pumping routines produce minimal milk and major stress.
Others breast-feed as much as they can, for months or even years.
"Dealing with low milk supply, it's whatever keeps you sane — that's the most important thing to do," says Retter, 28, who has been breast-feeding her daughter for two years, supplementing with formula and documenting her experience at her blog, Diary of a Lactation Failure. "If (breast-feeding) works for you, it's worth it to pull through the really hard days, because once you get an older nursing baby, it's a lot of fun."
Past study showed promise
Dr. Corrine Kolka Welt says she gets calls all the time from women with low milk supply who want to try prolactin.
But Welt, an associate professor at Harvard Medical School and Massachusetts General Hospital who did a promising pilot study in which injections of prolactin, a hormone that triggers milk production, increased milk supply in mothers of pre-term babies and women with prolactin deficiencies, has nothing to offer the women who call. Genzyme, the company that produced the form of prolactin she used in her study, has since stopped making it, and no one else has stepped in.
Although many women suffer from chronic low milk supply, they only do so for a limited amount of time, Welt says. That makes medications less profitable than, say, insulin or Viagra, which patients use for years.
"If someone would take this up and make it, I think there would be a lot of women who would be interested in trying it," Welt says.