Does smoking marijuana affect a womans chances of getting pregnant? my wife smokes ciggarettes a lot and smokes a blunt or 2 everyday

Cigarettes are worse: Marijuana may decrease fertility (and a blunt or 2 every day is quite a lot), but tobacco cigarettes are proven for sure to cause many pregnancy complications, basically by reducing the blood supply and nutrition which can get to a growing fetus (baby). My advice would be to stop smoking cigarettes and start taking prenatal vitamins before trying to get pregnant, and also decrease marijuana.

Likely so: Like tobacco it depends some on how much you use. Cigarettes are thought to reduce fertility by about 15% per-cycle . Marijuana has many more combustion byproducts than tobacco, so it's reasonable to believe it's at least as harmful.