We investigated the prevalence of abnormal screening results (questionnaire and testing for other causes of oligo-ovulation, male or tubal factor infertility) in a group of 1,313 oligo-ovulatory women (included and excluded subjects) whose condition was screened for inclusion in the Pregnancy in Polycystic Ovary Syndrome trial, a multicenter clinical trial that was conducted at 13 sites in the United States. Other than failure to demonstrate laboratory evidence of hyperandrogenemia, the most common reasons for subject exclusion were persistent oligospermia and tubal factor infertility.