"Our findings suggest that avoiding use of just one of these substances can decrease the pregnancy risks we see when both substances are used together, which is a critical piece of information providers can highlight when counseling patients," Dr. Adam Crosland, assistant professor of obstetrics and gynecology in the Oregon Health & Science University School of Medicine and the study's lead author, said in a press release. Researchers also found that infants whose mothers used both cannabis and nicotine during pregnancy were more likely to be born underweight and premature. What the Study FoundPrenatal cannabis use is more prevalent than ever, with up to 30 percent of pregnant women in younger, urban populations using the drug, according to the study, published in the Journal of the American Medical Association Network Open. "With the growing legalization of cannabis around the country, there is often a perception that cannabis is safe in pregnancy," Dr. Jamie Lo, an