Pregnancy outcome after IVF and ICSI in unexplained, endometriosis-associated and tubal factor infertility

BACKGROUND: This study was undertaken in order to compare pregnancy outcome after IVF and ICSI in unex-plained and endometriosis-associated infertility using tubal factor infertility as controls. METHODS: This was a retrospective cohort study of early IVF/ICSI pregnancies verified by serum hCG measurement, comparing the subsequent outcome in unexplained (n 5 274) and minimal endometriosis-associated (n 5 212) with tubal factor (n 5 540) infertility as controls. From January 1990 to December 2002, 1026 conception cycles after treatment with IVF or ICSI complied with the inclusion criteria. RESULTS: Live birth rate, twin birth rate after transfer of two embryos and abortion rate prior to 6 weeks of gestation were superior for the unexplained (78.8, 23.5 and 11.7%) compared to endometriosis-associated (66.0, 15.0 and 19.3%) and tubal factor (66.7, 18.1 and 18.0%) infer-tility groups (P < 0.05). Compared to the endometriosis-associated, the unexplained infertility group attained a higher pregnancy rate after the first treatment cycle (P < 0.05). CONCLUSIONS: The overall better outcome for the unexplained infertility group with respect to live birth rate, twin birth rate and early abortion rate compared to the minimal peritoneal endometriosis-associated and tubal factor infertility groups might be a guide to select diagnostic groups for single embryo transfer and be useful in patient counselling. Key words: endometriosis/IVF/pregnancy outcome/unexplained infertility