my wife smoked a couple times a week during her first pregnancy. it actually helped her in many ways. besides blinding the uncomfort, it helped the stress of having a child. she was real mellow, sometimes it gave her the energy she was looking for so she could go on walks. Although she did feel guilt, scared that our child was getting the high as well... i looked into it and couldnt not find a single side affect on the unborn child. i believe that it can via blood stream, but i dunno the science behind it.
I read an article of a woman who has done a 20 year study of cannabis and pregnancy. if i find it, i will post it up. She found no ill side affects. On the other hand, she has concluded that the children were better adapted to the real world once outside the womb. I have to say, both my kids were very calm and assertive. they didnt cry often unless hungry or shit themselves.
My daughter is way beyond her age. she is showing an immense interest in reading, she is only 3. her vocabulary is top notch. she loves being outside and learning about everything around her. its actually really hard to keep up with. Im not saying my wife smoking is the cause by any means, but after reading that article i kept an eye out and thought maybe my wife smoking caused my kids to be well adapted after birth.... i dunno