Marijuana use during pregnancy: consequences for the offspring.

Abstract

I n considering the relationship between marijuana use during pregnancy and the effects on human offspring, the investigator cannot help but be impressed by the paucity of objective information available. This lack of a body of scientific data is surprising for a number of reasons, among which is that marijuana has played a role in countless societies around the world for thousands of years’ and, today, is not limited to a select (either in terms of numbers or in terms of reproductive risk) few women of reproductive age. The extent of marijuana use by pregnant women has been examined by several investigators. Boston City Hospital inner city respondents reported usage between 10% to 2O%.‘,s In a relatively low-risk population at the Yale-New Haven Hospital, 4 it was estimated that 10% of the women delivering used marijuana during pregnancy. Among another low-risk home delivery population in California, 13% reported use of marijuana during pregnancy5 and in the Seattle, Washington area the rate was 16%.6 In Ottawa, Canada, usage information was gathered from a middle-class sample’ who volunteered to take part in a study described in detail later in this report. When interviewed during pregnancy and asked about prepregnancy habits, 80% of the women reported that in the year before pregnancy they did not use any marijuana, 12% used it irregularly, 3% smoked two to five joints per week, and 5% smoked on at least a daily basis. On recognition of pregnancy, usage declined significantly, but remained relatively constant during each of the trimesters, with 6%