[Cigarette smoking and time before pregnancy among Danish pharmacy assistants]

The relationship between time to pregnancy and cigarette smoking was studied in a group of 4,924 pharmacy assistants under 40. The information was collected by means of a self administered questionnaire and the response rate was 92%. The data were analysed by a recently developed statistical model for description of time to pregnancy, which provides a more revealing test than the classic contingency table analysis. The study shows that smokers have a median time to pregnancy which is 27% longer than for non smokers. This may partly be due to lifestyle associated with smoking (e.g. alcohol and caffeine intake). Lifestyles such as these have been reported to prolong time to pregnancy. It is shown that time to pregnancy is an easily obtained measurement of fecundity. Only 3.6% of the women were unable to remember their time to pregnancy. The conclusion of the study was that information pertaining to the relationship between fertility and smoking habits/lifestyle should be a part of the instruction for women who wish to become pregnant.