Smoking and female fecundity: the effect and importance of study design

This review evaluates the evidence for a link between smoking and female fertility. Twenty-two primary papers and two reviews were found. All but three indicated a detrimental effect of smoking on reproduction despite varying considerably in their approach, definitions used and populations studied. The strength of association is small but statistically significant and a dose response relationship suggests the theory that smoking is causative. Poor design in particular and the failure to assess confounders weakened many studies and should be addressed in future studies.(C) 2003 Elsevier Ireland Ltd. All rights reserved.