Abstract
To determine the characteristics of couples with resolved subfecundity and to compare these findings in twogeographically distant centres, a self-reporting questionnaire was completed by a sample of women attending six antenatal clinics in Greater Manchester, UK and five antenatal clinics in Melbourne, Australia. A total of 2158 pregnant women, 1106 from Manchester and 1052 from Melbourne participated in the study. The prevalence of subfecundity (proportion of women who failed to conceive current pregnancy within 12 months of unprotected intercourse) and demographic and medical factors potentially related to subfecundity were measured. The samples from the two cities had similar medical characteristics, but several socioeconomic and cultural differences were detected. Characteristics which independently correlated with decreased fecundity were increasing parental age, previous pregnancy, previous miscarriage, maternal smoking before conception and low socioeconomic status. Increased body mass index was also a significant, independent predictor of decreased fecundity, but in the Melbourne sample only. Subfecundity was found to be influenced by a combination of parental and socioeconomic factors as well as previous pregnancy. The factors identified were similar in two modern industrial societies in very different geographical locations, only their relative importance differing between Australia and the UK.