Successful implantation of an invading embryo requires a normal functioning endometrium along with a healthy myometrium; thus, several uterine abnormalities could play a key role in recurrent implantation failure (RIF). The aim of this chapter is to review the existing evidence of the association between acquired uterine conditions and RIF and to discuss treatment results on reproductive outcome.

There is sufficient evidence that submucosal fibroids negatively affect implantation and their hysteroscopic excision ameliorates the probability of successful pregnancy, as well as that subserosal fibroids do not influence implantation. Thus, myomectomy does not offer any beneficial effect in the case of intramural fibroids. Intramural fibroids not distorting the endometrial cavity might negatively impair IVF outcome, especially if there are more than one and/or they are larger than 3–4 cm in diameter.

Although there is still no general consensus on the impact of adenomyosis on a woman's implantation potential and on the potential benefit of adenomyomectomy or GnRHa treatment, both of them appear to be reasonable options in cases of patients with adenomyosis and RIF.

It is well documented that endometrial polyps could cause RIF in IVF patients; thus, in this group of patients, hysteroscopic polypectomy should be recommended. The presence of intrauterine adhesions might be related to impaired implantation and RIF; thus, hysteroscopic adhesiolysis should be offered to women undergoing IVF.

Although more data are needed to elucidate the exact role of chronic endometritis on implantation and the work-up for its diagnosis, there is evidence to support that this condition provokes an unfavorable effect on implantation and that antibiotic therapy should be given followed by hysteroscopic reevaluation.