Cigarette Smoking, Alcohol Consumption, and Caffeine Intake and Fecundability

Background. In a prospective study the effect of the behavioral risk factors of both partners on fecundability was studied. Methods. Information was collected on smoking habits, alcohol consumption, and caffeine intake (e.g. coffee, tea, and cola consumption) by interviewing 259 female nonmedical hospital workers, i.e., clerical staff, cleaners, kitchen and restaurant workers, and their partners, who were planning a pregnancy. The occurrence of pregnancy was tested prospectively during the 12 months after enrollment. Results. Among the participants as well as among their partners, smoking a moderate number of cigarettes (1-10/day) was associated with higher fecundability (i.e., the probability of becoming pregnant each month) than among those not smoking (participant: OR = 1.4 (95% CI, 0.9-2.2); partner: OR = 2.1 (95% CI, 1.2-3.5)). The level of alcohol consumption in the female partner was not related to fecundability. However, in the male partner, there was a positive influence for drinking more than 10 alcoholic drinks per week compared with that observed for those drinking less than 5 (OR = 1.6; 95% CI, 1.0-2.4). Participants with a moderate caffeine intake (400-700 mg/day) showed a higher fecundability than those with a lower intake level (ORadjusted = 2.1 (95% CI, 1.2-3.7)). Heavy caffeine intake (>700 mg/day) among partners was negatively related to fecundability when compared with the lowest intake level (ORadjusted = 0.6 (95% CI, 0.3-0.97)). Conclusions. This study does not support the hypothesis that moderate cigarette smoking, caffeine intake, and alcohol consumption have an adverse influence on fecundability.