My mom was (and still is) a smoker, but I doubt she did during pregnancy. She said she did have toxemia, and that is caused by high blood pressure. What can cause that? Nicotine. She normally has lower than standard blood pressure, as do I without the use of stimulants. So, my guess is that she may have quit somewhere after finding out rather than immediately. I wasn't born prematurely, and I had no cognitive delays, but I did end up with Asperger's Syndrome and ADHD Inattentive Type. I don't see either of those as delays; just differences. Plus, along with having a misaligned body and brain I also seemed to end up mosaic XXY. So, I'm quite a mess. I would consider those things as being genetic, though, rather than a result of smoking, but I'm no doctor.