Most studies have focused on general rather than infertile populations and have relied on the collection of retrospective data, leaving them open to recall bias. However, Willcox et al [3] conducted a prospective study of 104 women attempting pregnancy. Caffeine consumption was recorded at regular intervals as well as daily information regarding menstrual bleeding and intercourse until pregnancy occurred. Women who consumed less than one cup of coffee were twice as likely to become pregnant, per cycle, as moderate coffee drinkers and the risk of not becoming pregnant increased with higher consumption. Other studies have also suggested an association between caffeine intake and increased time to conception that may be dose-response related [9].