You bring up an interesting point in your last paragraph. My mother did not smoke, ever, but all my young life I was in households with people who did, and it was not unusual for me to be in a room that was visibly fogged with cigarette smoke. The more interesting point I'd like to make, though, is that I DID smoke while I was pregnant with all three of my children. They range in age now from 37 to 43, so they were born before it was well known that smoking had ill effects on prenatal babies.
All three of them have been smokers at one time or another, but only one still smokes now. However, they all have had psychological challenges in the form of depression, general anxiety disorders, and bipolar disorder. I believe my maternal grandmother was bipolar, so that may have been a hereditary thing, but two of my three kids have that dx. My first baby was premature - I had pre-eclampsia that put me in the hospital at 33 weeks - and she was like a raw nerve for the first five or six years of her life. She also is one of the ones who is bipolar now, and she takes meds for it, both to keep cycling under control and to help her get some decent sleep at night. My son medicates himself in various ways that are inappropriate to discuss here, but he is in a fairly good spot right now, thank God.
I do believe that smoking has ill effects on babies. I also believe that general anesthetics for Caesarian sections have ill effects on the babies if the anesthetic is not managed exactly right. Of my three children, all of whom were born by c-section, I believe my son was the one whose birth was not properly managed, and isn't it such a coincidence that he is the one with the most serious problems now? My daughter who is bipolar was also born under general anesthetic. Hmmm.......
This is just a long-winded way of stating the obvious - we are exposed all the time to heaven-knows-what, in petroleum fumes, pesticides, household cleaners like ammonia, first- or second-hand smoke, additives in food, antibiotics in meats, the medications we take, ad infinitum. There is no telling how we are affected. Smoking is only one piece of the puzzle, but there's no doubt in my mind that I am better off without it, and I would be better still if I were not exposed to second-hand smoke in my house. I wish I had not smoked while pregnant, but even more than that, I wish I had taken an epidural for all three c-sections instead of just the last one.