Still, "methadone hasn't been studied as well as we would like," he said.
There is no direct evidence that babies are harmed over the long term by methadone. Often the children grow up in chaotic homes, where they may see violence, be exposed to lead paint and attend subpar schools or have mothers who return to hard drugs and the lifestyle that goes with them.
"It's hard to tease out how much is the drug specifically and how much is the environment," Welsh said.
According to 2007 federal data, approximately 5 percent of pregnant women ages 15 to 44 admitted to having used illegal drugs in the past month, significantly lower than the 9.7 percent of non-pregnant women in that age group. Many also use alcohol or smoke cigarettes while pregnant. They know the risks that drug use poses to their unborn children. But that doesn't mean they are ready to abandon habits that have become part the fabric of their lives.
"There's a tremendous amount of guilt and stigma that these women walk in the door with," said Hendr?e Jones, research director at the Center for Addiction and Pregnancy. "They know putting a drug inside their body is harming them and the baby. They shoot up and they cry."
The Bayview center, which is also known as CAP, has been around for nearly 20 years. It was born out of a methadone clinic that in the mid-1980s started seeing a handful of pregnant women on its doorstep. Women weren't its usual clients then, let alone those expecting children.
The director of the clinic wasn't comfortable giving methadone to pregnant women, Walters said. But he did want them to get prenatal care. The women weren't interested. So he brought in an obstetrician and made check-ups mandatory if they wanted methadone. He got 100 percent compliance.
In 1991, CAP opened its doors. The idea was a "one-stop-shopping model," Jones said. There is methadone distribution, individual and group therapy, nutrition counseling, an obstetric clinic and a pediatric clinic. Most of the women are in extensive outpatient treatment, but many start out in the residential unit, which can be used for detox or as a timeout of up to 28 days from a drug-using life on the streets.
CAP used to offer more programs than it does now, but 98 percent of its patients are on medical assistance, and Medicaid doesn't pay for what it once did. Once the center sent vans into the neighborhoods to pick up the women; now staff give out bus fare. They used to treat women for two years after the births of their babies. Now, they're covered only for a maximum of three months.
