Fertilization with human testicular spermatids: four successful pregnancies

Between July 1995 and May 1996, 36 patients with non-obstructiveazoospermia of secretory origin underwent intracytoplasmic injection ofspermatids. 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. Theejaculate was duly examined and a complete absence of spermatozoa andspermatids was confirmed, with only bacteria and debris being found.Testicular sperm extraction (TESE) was then performed. In 19 out of 36cases round spermatids only were found, while elongated spermatids werefound in the remaining 17. Both round and elongated spermatids wereisolated and used for injection. A total of 135 oocytes at metaphase IIwere recovered from 19 partners and injected with round spermatids, while123 mature oocytes from 17 partners were injected with elongatedspermatids. The number of oocytes fertilized, as judged by the presence oftwo pronuclei, was 75 (55.5%) and 71 (57.7%) respectively. By 34 h afterinjection, the number of embryos which had cleaved to the 2-cell stage was56 (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 spermatidcycles (10.5%) (both are still ongoing), and three cases of elongatedspermatid cycles (17.6%) (two are still ongoing; one was lost after 8 weeksof gestation). Chromosomal analysis showed that all fetuses had a normalkaryotype (three male and one female) with no chromosomal abnormalities.