Uterine fibroids may cause infertility, depending on their size and their location [1]. The mechanisms linking uterine fibroids and infertility are numerous: uterine cavity distortion according to the FIGO classification; impaired endometrial and myometrial blood supply; increased uterine contractility; hormonal, paracrine and molecular changes; impaired endometrial receptivity and gene expression (decrease in homeobox 10 [HOXA-10] expression); and thicker capsule. The effect on infertility of fibroids distorting the cavity is easy to understand. We will also review the influence of non-cavity-distorting intramural fibroids.

Endometriosis is a benign estrogen-dependent gynecological disease, known to occur in 7–10% of women of childbearing age [1, 2]. This percentage may rise to 30–50% if only women presenting with pelvic pain and infertility are taken into account [3]. The condition is histopathologically defined as the presence of endometrial tissue (glands and stroma) in ectopic locations outside the uterine cavity. It is now widely recognized that three different forms of endometriosis can occur in the pelvis, namely peritoneal endometriosis, ovarian endometriosis, and deep endometriotic nodules of the rectovaginal septum, each with its own pathogenesis [4].

Although the clinical presentation of endometriosis includes dysmenorrhea (painful menstruation), dyspareunia (painful sexual intercourse), and chronic pelvic pain, infertility is still regarded as the biggest concern for endometriosis patients [5, 6]. The presence of intraovarian endometriomas in particular can cause follicle loss, diminishing the ovarian reserve and consequently leading to infertility [7, 8].

Fertility preservation is now recognized as the most essential quality of life issue in young cancer survivors. Since the last decade several strategies to preserve fertility in women have been developed and applied clinically (although some are still experimental). Ovarian tissue cryobanking is currently perceived as a promising technology for fertility preservation which draws enormous attention not only from scientific communities but also from the general public. Ovarian tissue cryopreservation followed by transplantation has proven to be very successful not only in many animals but also in humans. Indeed, we have accumulated enough data since 2004 that ovarian transplantation can restore fertility in women. As of 2018, approximately 130 healthy babies have been born worldwide after transplantation of frozen-thawed ovarian tissue [1–9].

The first live birth to occur after ovarian-tissue transplantation between two genetically different sisters was reported in 2011. Since this is an acceptable practice with monozygotic twins, there is no apparent reason to refrain from using it with genetically different sisters, especially if one of the sisters previously received bone marrow from the other, leading to complete chimerism (HLA compatibility) between donor and recipient, thus obviating the need for immunosuppressive treatment. This approach allows for natural conception, which could be important on moral, ethical or religious grounds.