**2.1 Identification and eligibility of relevant studies**

Medline searches (up to March 2011) were performed using various combinations of terms: ectopic pregnancy, heterotopic pregnancy, *In Vitro* Fertilization, Intrauterine Insemination, pelvic inflammatory disease, Chlamydia trachomatis, heterotopic pregnancy, cervical pregnancy, cost-effectiveness.

The search was complemented with perusal of the bibliographies of retrieved papers and review articles. We included studies that evaluated the presence of an ectopic pregnancy after IVF in case reports, although in other chapters information was obtained from studies in the general population.

Number of tested samples was not an exclusion criterion. Only studies including human subjects were included.
