Fertilization, pregnancy and embryo implantation rates after ICSI in cases of obstructive and non-obstructive azoospermia

Abstract

The aetiology of azoospermia can be grossly divided into obstructive and non-obstructive causes. Although in both cases testicular spermatozoa can be used to treat male fertility, it is not well established whether success rates following intracytoplasmic sperm injection (ICSI) are comparable. Therefore, a retrospective analysis of fertilization, pregnancy and embryo implantation rates was performed following ICSI with testicular spermatozoa in obstructive or non-obstructive azoospermia. In total, 193 ICSI cycles were carried out with freshly retrieved testicular spermatozoa; in 139 cases of obstructive and 54 cases of non-obstructive azoospermia. The fertilization rate after ICSI with testicular spermatozoa in non-obstructive azoospermia was significantly lower than in obstructive azoospermia (67.8% versus 74.5%; P = 0.0167). Within the non-obstructive group, the fertilization rate in the group of maturation arrest (47.0%) was significantly lower than in case of Sertoli cell-only (SCO) syndrome (71.2%) or germ cell hypoplasia (79. 5%). Embryo quality on day 2 after ICSI was similar for all groups. Pregnancy rates per transfer between obstructive (36.8%) and non-obstructive groups (36.7%) were similar. In cases of maturation arrest the pregnancy rate per transfer was lowest (20.0%) although not significantly different from SCO syndrome or hypoplasia groups. Embryo implantation rates were not different between the obstructive (19.6%) and non-obstructive groups (25.8%), and were lowest in cases of germ cell hypoplasia (15.8%). This retrospective analysis shows that although fertilization rate after ICSI with testicular spermatozoa in non-obstructive azoospermia is significantly lower than in obstructive azoospermia, pregnancy and embryo implantation rates are similar.

Sperm defect severity rather than sperm source is associated with lower fertilization rates after intracytoplasmic sperm injection

“…Therefore, it is reasonable to speculate that the fertilizing potential of these gametes may differ. In fact, ICSI outcomes with testicular spermatozoa from nonobstructive azoospermic men have been poorer than ejaculated and epididymal sperm (2)(3)(4)21). In addition, miscarriage rates after ICSI with testicular spermatozoa have been reported to be higher (5,7), although a clear distinction in the type of azoospermia is not always possible to analyze.…”

“…Before ICSI, sperm from men with severely defective spermatogenesis, such those with oligoasthenoteratozoospermia, and sperm retrieved from the epididymis or the testicles, were unable to fertilize the egg -even through conventional in vitro fertilization. When microinjected into the egg using ICSI, however, these gametes have shown the capability of diluting their genetic material, fertilizing and producing normal and viable pre-embryos (1)(2)(3)(4)(5)(6)(7)(8). Although the use of surgically retrieved or ejaculated sperm from men with severely impaired spermatogenesis for ICSI has greatly improved treatment of severe male infertility, the consequences of using such gametes are not fully known (7).…”

“…Many studies have shown conflicting results when ICSI is performed with sperm from different sources (2)(3)(4)(5)(6)(7)(8). It is difficult to interpret these results because, apart from few studies, only the sperm source is analyzed and there is no systematic distinction between obstructive and non-obstructive azoospermia.…”

Tissue Perfusion Essential for Spermatogenesis and Outcome of Testicular Sperm Extraction (TESE) for Assisted Reproduction

“…Due to the introduction of ICSI (4) and in combination with tes- ticle biopsy (16,17), motile sperm could be selected from azoospermic patients and utilized in ART. By employing a variety of different sperm retrieval and biopsy techniques depending on patients' infertility syndromes, the fertilization capacity for these differently retrieved sperm has resulted in appreciable ICSI successes rates, leading to pregnancies and deliveries (18)(19)(20)(21)(22)(23). Men who suffer from azoospermia have now the opportunity to fertilize their partners' oocytes with their own sperm to obtain children from their own genetic profile.…”

Frozen Embryos Generated from Surgically Retrieved Sperm from Azoospermic Men: Are They Clinically Viable?

“…Overall, the majority of large series of ICSI cycles from azoospermic men, using both fresh and cryopreserved sperm and from either obstructive or non-obstructive cases of azoospermia have reported excellent fertilisation (56-81%) and clinical pregnancy outcome (24-37% per embryo transfer) (9)(10)(11)(12)(13)(14)(15).…”