I started smoking in my late teens, some 40+ years ago. I smoked through both my pregnancies, and continued to smoke. I had 8+ lb babies who had no respiratory problems. Smoking was permitted in the day room in the maternity unit. My husband has never smoked, neither have my offspring.
I did manage a five-year break when my offspring were still quite young, but then went to university where I was surrounded by many 18-year-olds who smoked. After a term of passive smoking I caved in and was quickly back up to 20 a day. That was back in the 1980s and I've not managed to quit again.
My daughter got married last year. Should we get that "we're expecting" phone call, the cigarettes are going to have to go. There's no way she or my son-in-law would allow their young baby in this house if I continue to smoke. They both have an attitude about that, and I love them for that.
My offspring are now more than old enough to specify their ground rules. Back then I didn't know that I should have listened to their unspoken request to breathe uncontaminated air. But then, as I said, smoking was permitted in the day room, and if you were around just before the 6 a.m. roll call (as I often was - 10 day stay for the first birth) the day room was the favourite place for the midwives to hang out with coffee and fags before going off duty.
Are parents who smoke selfish? Yes, in a way they are, as was I. But it's an incredibly difficult addiction to deal with. Stopping could probably introduce an extra level of stress on top of what is normally experienced in pregnancy and after. Focussing on the "selfishness" is one way of looking at it, but there does need to be much more knowledge of why certain people are more prone to that kind of addiction, and a better way of enabling them to find ways of managing that, without condemning them as solely "selfish". It's a very, very tough addiction to get rid of.