Nearly 20 per cent of the babies born at Meno-Ya-Win health centre in Sioux Lookout have been exposed to opioids, like oxycontin.
Hospital officials said the number of babies experiencing withdrawal doubled from 2009 to 2010 and continues to increase.
Meno-Ya-Win has doubled its maternity staff to help deal with the situation.
Leanne Tyler is a clinical co-ordinator at the health centre.
"We don’t want anyone going through withdrawal; it's incredibly uncomfortable," she said.
"Adults can tell us the … discomfort they're feeling. Babies can't, right? So that's why we watch for those symptoms of the nausea, the vomiting the diarrhea."
By the end of this year, the hospital expects it will have delivered about 400 babies — 50 more than last year. Meno-Ya-Win serves the fly-in First Nations north of Sioux Lookout, as well as the town.
Tyler said doctors and nurses do their best to discover whether pregnant women are using drugs.
"It’s such a difficult conversation to have with the mothers … you're asking them, not so much for their health, but, for the safety of the baby."
Some infants suffer life-threatening problems such as seizures because of their exposure to opioids.
Barb Linkewich, vice president of health services at Meno-Ya-Win, said the hospital is looking for more help.
"We'd also like to work with the moms with the community workers … but so far we haven't … this is a new problem that is growing."
Meno-ya-Win opened a new medical withdrawal unit on December 5 to help adults with the painful process of breaking an addiction to prescription drugs. It has five beds, some of which may be available to pregnant women.