The general consensus is that infertility evaluation should be undertaken for couples who have not been able to conceive after 12 months of unprotected and frequent intercourse. In women between 35 and 40 years of age, most initiate evaluation after 6 months of unprotected intercourse without conception, and immediate evaluation in women over 40 years of age. Evaluation is initiated sooner if the female partner has a history of oligomenorrhea/amenorrhea, pelvic infection or surgery, chemotherapy and/or radiation, or endometriosis.
Male factors can also be indications for initiating early evaluation of the male partner. These factors include a history of testicular trauma requiring treatment, adult mumps, impotence or other sexual dysfunction, chemotherapy and/or radiation, or a history of subfertility with another partner.
See detailed steps of the standard fertility work-up at UpToDate.com
* Success rates for IVF range from 10 - 40% depending on age, facility, and other factors. When selecting a clinic for IVF/ART, consider checking its Fertility Clinic Report on the CDC website.
Here's a sample of what you will learn (this data from Brigham and Women's Hospital ART Center in Boston):