In the worst case, the foetus may die in the uterus, but even if the child survives, its immune system may be weakened by the effects of tobacco. ... Premature babies, i.e. those born before the 37th week of pregnancy, suffer more from illness and have a higher death rate, studies suggest that premature birth and smoking are connected. 50% of women who smoke are at increased risk of giving birth prematurely. ...