ABSTRACT
Background: repeated implantation failure [RIF] is defined as pregnancy failure after two to six times with at least ten high grade embryo transfer to uterus. A variety of causes have been anticipated for RIF, including anatomical, autoimmune, genetics, endocrine and thrombotic anomalies. Factors responsible for RIF have important implication regarding treatment however in many couples a perfect cause cannot be found
Cases: in these case series, we reported nine couples with RIF that after investigation no definitive etiology was found for RIF and empirical therapy by heparin, aspirin and or immunotherapy was not effective. In these cases we recommended transfer of embryos to surrogate uterus. Nine patients were studied and six of them developed a normal pregnancy [pregnancy rate=66.66%]
Conclusion: this study showed that surrogacy is a good option for treatment of RIF