Comparisons will be made to those declining NPT treatment, waiting for NPT treatment, receiving other treatment, or stopping treatment. The investigator seeks to document specific pregnancy rates for different factors such as age and type of infertility diagnosis. Investigators will also assess characteristics of environmental exposures that may be associated with infertility. Couples will be followed for up to three years, regardless of when they begin NPT treatment, or whether they continue treatment. Data from all couples will be useful for this study, regardless of their individual circumstances or actual treatment.