[judgemental statement]
People (especially those with families) who understand that smoking kills both themselves and people around them and still continue to do nothing to try and stop are among the most selfish people I know.
[/judgemental statement]

How about this. My friend's girlfriend (who smokes and drinks) recently found out she was pregnant. When she found out she was pregnant, I believe she was already 5 months! She had been smoking and drinking all that time. Even worse, she hasn't stopped. That is a shame, and very sad. I must agree with your statement, and in this case, at least for the sake of the baby, expectant moms must be responsible.

Unfortunately, outside of the strong urging, coercing, etc that myself and all my friends have done, she won't/can't quit.