Women have a lower chance of getting pregnant in their first year trying to conceive if they have a history of heavy, prolonged smoking, according to a study co-authored by Boston University School of Public Health (BUSPH) researchers. Teams from BUSPH and Aarhus University Hospital in Denmark compared the chance of getting pregnant among 686 current smokers, 741 former smokers, and 2,346 never smokers from a study of women in Denmark who were attempting pregnancy. The study, published online in Fertility and Sterility, is the first to analyze former smokers according to how many cigarettes they smoked per day and for how long.