Your question was with regard to maternal cannabis use and if there are effects on the fetus. There have been a few limited studies, longitudinal studies, that have looked at that, and they found some subtle long-term effects on children born to mothers who had used cannabis during pregnancy. What those long-term effects were, the actual impact in everyday life, I'm not sure they were clearly demonstrated, but in terms of laboratory measures of cognition and other neurocognitive faculties, they found subtle impairments in certain aspects of memory among children who were born to mothers who had used cannabis during pregnancy.
On May 1st, 2014. See this statement in context.