Endometriosis is an estrogen dependant disease of high morbidity, infertility being one of symptoms. Briefly, three different entities have been described, namely peritoneal, ovarian (endometrioma) or deep infiltrating, and these frequently coexist. Due to the lack of a reliable non-invasive method for its diagnosis, it is difficult to estimate its true prevalence. Studies report its prevalence to be about 10% in the general population and a contributing factor in causing infertility in approximately 40% of women. It is also estimated that about 50% of women with endometriosis have difficulty in getting pregnant (1).
Although a direct causal relationship with infertility cannot be made, it is shown that the fecundity rate of untreated women can go as low at 2% (2). The impact exerted by the disease on oocyte quality / quantity and ultimately on the embryos, make this pathology a subject of constant study and interest for infertility specialists. It is assumed that this generalized disease causes a damage due to production of cytotoxic chemicals and also by disturbing the pelvic anatomy. Focal lesions like endometrioma can be more harmful due to its additional space occupying effect. It is also found that the disease itself and its surgery can damage the ovarian reserve and hence this disease is of interest (3).
Dr. Carl Wood of the Monash IVF team in Melbourne reported the first IVF pregnancy in 1973, although it resulted in an early miscarriage, started a new era. Medical history was made on July 25, 1978, with the birth of the world’s first “test tube baby” by performing a natural cycle IVF. Trounson et al. in 1981 introduced ovarian stimulation (OS) in IVF and this led to higher pregnancy rates (4). These ovarian stimulations consist basically of the administration of urinary or recombinant gonadotropins, used alone or in conjunction with Letrozole or Clomifene. Premature LH peak is usually prevented with the use of GnRH analogues (agonists and antagonists) or more recently by the use of oral progesterone (5,6). Thus, discussions have arisen over the years about which is the best OS protocol for these patients with endometriosis when undergoing fertility treatments. This population also frequently undergoes ovarian surgery to remove the endometriotic cysts, and, therefore, may also present impairment of the ovarian reserve (6). Optimizing treatments and seeking the best protocols in order to obtain satisfactory amounts of oocytes and embryos of good quality is crucial to achieve reproductive success.
Preparations prior to OS have also been proposed, with the aim of obtaining a more synchronous follicular development, limit the growth of the endometriotic implants and reducing the chronic pelvic inflammatory process, which supposedly could negatively impact treatments. These have also been used post OS but prior to performing a frozen embryo transfer with the same purpose. These protocols include the use of long periods of oral contraceptives, depot GnRH agonists and/or even intrauterine hormonal devices (7,8).
This chapter will have a special emphasis on the peculiarities and results of using the aforementioned protocols, comparing them with each other and with patients without endometriosis.5 – IVF stimulation protocols and outcomes in women with Endometriosis
