Fertilization with human testicular spermatids: four successful pregnancies

Abstract

Between July 1995 and May 1996, 36 patients with non-obstructive azoospermia of secretory origin underwent intracytoplasmic injection of spermatids. A previous histological biopsy was performed on all patients: 15 had spermatogenic arrest, a further 13 had Sertoli cell-only syndrome, and the remaining eight had post-cryptorchidism tubal atrophy. The ejaculate was duly examined and a complete absence of spermatozoa and spermatids was confirmed, with only bacteria and debris being found. Testicular sperm extraction (TESE) was then performed. In 19 out of 36 cases round spermatids only were found, while elongated spermatids were found in the remaining 17. Both round and elongated spermatids were isolated and used for injection. A total of 135 oocytes at metaphase II were recovered from 19 partners and injected with round spermatids, while 123 mature oocytes from 17 partners were injected with elongated spermatids. The number of oocytes fertilized, as judged by the presence of two pronuclei, was 75 (55.5%) and 71 (57.7%) respectively. By 34 h after injection, the number of embryos which had cleaved to the 2-cell stage was 56 (74.6%) with round spermatids and 55 (77.4%) with elongated spermatids. All cleaved embryos were transferred into the uterus of the partners. Clinical pregnancies were established in two cases of round spermatid cycles (10.5%) (both are still ongoing), and three cases of elongated spermatid cycles (17.6%) (two are still ongoing; one was lost after 8 weeks of gestation). Chromosomal analysis showed that all fetuses had a normal karyotype (three male and one female) with no chromosomal abnormalities.

The First Successful Pregnancy Following Injection of Testicular Round Spermatid in Iran

“…Tesarik et al [12,16] reported 7 cycles of ROSI (Sa type) with 46% fertilization rate with 10% of syngamic zygotes. Antinori et al [17] reported a 56% rate of fertilization, while Vanderzwalmen et al [18] reported 12% fertilization. Since successful pregnancies have been reported after round spermatid injection, we are encouraged to attempt the use of testicular round spermatid (Sa) obtained in a biopsy sample of a nonobstructive azoospermia.…”

Primate models for assisted reproductive technologies

“…Several normal clinical pregnancies following round spermatid injection have been reported (Antinori et al 1997, Kahraman et al 1998, Barak et al 1998, although disappointingly poor fertilization and subsequent embryonic development are common outcomes (Levran et al 2000, Vicdan et al 2001. Fertilization of cynomolgus macaque oocytes with round spermatids has been reported; however, the only pregnancy established aborted at day 103 (Ogonuki et al 2003).…”

Limits to the clinical Application of ICSI.

“…Round or elongated spermatids were collected from patients with non-obstructive azoospermia who did not have mature spermatozoa in their testes, and some of their partners became pregnant and delivered babies. Table 1 summarizes the major reports on round spermatid injection [39][40][41][42][43][44][45][46][47][48]. As can be seen in the table, the rates of fertilization and delivery had been low, but the cause of these poor results had not yet been clearly identified.…”

“…Artificial oocyte activation is therefore probably necessary when round spermatids are used in microinjection. Excessive ooplasm aspiration [39,40,42,43,45], calcium ionophore treatment [41,45], and electric stimulation [59] for artificial oocyte activation have been introduced when round human spermatids are used. But with these artificial oocyte activation methods, Ca 2+ oscillation is not induced.…”