In Patients with Only One or Two Oocytes, Is IVF-ET or ICSI Better?

Abstract

One of the aims of assisted reproduction technologies (ART) is the recruitment of multiple follicles ensuring the recovery of good-quality oocytes upon controlled ovarian hyperstimulation (COH). In recent years, the number of patients in whom few oocytes are obtained in response to COH is increasing. This phenomenon mainly is probably related to the postponement of childbearing to the fourth decade of life. In this group of patients, multifollicular response to COH remains a challenge, but the optimisation of laboratory strategies may help to maximise their chances of pregnancy. Ovarian response to COH varies widely among patients and is strictly dependent on the size of the ovarian pool of resting follicles, the so-called ovarian reserve [1]. In women with a reduced ovarian reserve, a poor ovarian response results in a low number of retrieved oocytes despite the high dose of gonadotropins administered. Hence, although tests for predicting ovarian reserve are available [2], the parameter that best categorises a woman as a ‘poor responder’ remains the ovarian response itself. The incidence of poor ovarian response (POR) is estimated between 9 and 24 % [3–5]. This value increases with age [3, 5] reaching about 50 % in women over 40 years [6]. Women who respond poorly to COH have pregnancy rates that vary from 7.6 to 17.5 %, while in normal responders, they vary from 25.9 to 36.7 %. Female age plays a distinct role in predicting poor response to COH; in fact, older poor responders have lower pregnancy rates (ranging between 1.5 and 12.7 %) compared with younger poor responders (ranging between 13.0 and 35 %) [2]. A second predicting factor of pregnancy outcome in poor responders is the degree of poor response. A lower number of retrieved oocytes results in fewer embryos to transfer and a lower chance of pregnancy, in addition to the expected negative effect of poor ovarian function on oocyte quality.