My aunt smoked very heavily during both her pregnancies, her son was born perfectly healthy.
Her daughter was born full term but with a smaller birth weight (5 pounds 6 oz). She had to go into the NICU right away because she wasn't getting enough oxygen, and a little while after she came home she was diagnosed with asthma. She was hospitalized about twice a year until she was three because she couldn't breathe. She had to have breathing treatments once a day (twice on bad days, mostly in the summer though) and carried an inhaler with her (she rarely used the inhaler though, just if she got to close to any smoke, not just cigarettes) until around her 5th birthday..that winter the doctors had her taken off the treatments but with a humidifier in the room and nobody could smoke around her. During the summer she still needed the treatments until right before her tenth birthday, and now she has pretty much grown out of it unless the room is really dry or shes around smoke, but she doesn't require an inhaler she just moves away from the person smoking/grill/bonfire smoke. She's now 13 and is still small for her age, probably a full foot under her peers and has almost no weight on her at all, although that could just be her, she's a picky eater. She also matured faster and started her period at 9 although it could be unrelated. Everything she went through could have been completely unrelated to her mother smoking, or it could have been everything to do with it..you just never know.
Sorry for any typos/anything that doesn't make sense I'm on my iPad!
Also a funny story, my mom smoked all of our lives (started after she had us) and my sister was her mini me..she decided she wanted to smoke too..and started trying to get into the cigarettes and ashtrays any chance she got. Finally my mom lit one and gave it to her and she gagged and choked and to this day at 20 she can't stand to be around them.
My aunt also smokes and her daughter did the same thing my sister did, my mom gave her her advice based on her own experience with my sister and my aunt followed, my then 3 year old cousin took a big puff and said "oh man mama I like this!" My aunt could have killed my mom. She's 13 now and can't stand to be around them either