Cigarette smoking and waiting time to pregnancy: results of a pilot study.

Waiting time to pregnancy is an important characteristic of human reproductive health, which has not been investigated in Lithuania until now. Data on waiting time to pregnancy have been collected from medical records of 111 women admitted to the Department of Obstetrics, Klaipeda Hospital. Seven women in whom pregnancy was the result of infertility treatment were excluded from the analysis, and the rest 104 cases were analyzed. We evaluated waiting time to pregnancy in respect to the age of couples, contraceptive use, cigarette smoking of both partners, and some other features of obstetric history. The mean waiting time to pregnancy in the cohort was 5.21+/-7.03 months. If both partners smoked, the mean waiting time to pregnancy was significantly longer than in nonsmoking couples (7.68+/-9.41 vs. 4.30+/-5.73, P<0.05). Risk to have waiting time to pregnancy longer than 6 months was significantly higher if both partners smoked as compared to nonsmoking couples (OR 3.32, 95% CI 1.07-10.30, P=0.03), while paternal smoking and smoking of any partner did not increase this risk significantly. The other possible factors - age, living place (rural or city), previous contraceptive use, regularity of menstrual cycle, and frequency of intercourse - did not influence waiting time to pregnancy significantly. Results obtained from this pilot study enable us to plan and implement a larger-scale study of waiting time to pregnancy in Lithuanian population.