Is it harmful if you smoke marijuana while pregnant?

In a way, yes: Some of the toxins you inhale with every cigarette will enter your blood and travel thru the umbilical cord to baby.It is well documented that the newborn of a marijuana smoker will have a smaller skull volume & the question of related learning problems has conflicting findings.

Marijuana & pregnant: I agree with dr. Ferguson. Marijuana can also damage the placenta that nourishes your baby during pregnancy. http://www.sciencedaily.com/releases/2012/09/120912101806.htm in addition, research shows more likelihood of deficits in school achievement, & trouble with problem solving, memory, planning, impulsivity, attention, & depressive symptoms in kids who were exposed to it in utero.

Marijuana: Yes. Literature shows marijuana is potentially harmful to embryonic development as early as 2 weeks after conception. In-utero exposure has been linked to anencephaly, a condition in which the forebrain fails to form, as well as with later development of adhd, learning disabilities, memory impairment, depression, and aggression. Pre-1997 no detrimental effects on pregnancy were reported&believed.

Yes.: Yes. It is not wise to take drugs except vitamins especially in the first trimester of pregnancy.