PIP: The available scientific literature on the health effects of abortion on women in the US neither supports nor refutes the premise that abortion contributes to psychological problems. The 250 studies that have considered the psychological aspects of abortion are all flawed methodologically. Needed to resolve this issue is a prospective study of a cohort of US women of childbearing age focused on the psychological effects of failure to conceive, as well as the physical and mental sequelae of pregnancy whether carried to delivery, miscarried, or terminated by abortion. The most desirable such study could be conducted for about US$100 million over a 5-year period; a less expensive yet satisfactory study could be conducted for $10 million over the same time frame. Before such a study can be undertaken, a survey instrument must be designed to eliminate the discrepancy between the number of abortions on record and the number of women who admit to having an abortion on survey. Another issue is that the health effects of abortion cannot easily be separated from the controversial social issues surrounding pregnancy termination.