Pregnancy and birth after transfer of embryos that developed from single-nucleated zygotes obtained by injection of round spermatids into oocytes. 1998
OBJECTIVE To use injection of spermatids into oocytes as a mode of infertility treatment in cases in which spermatozoa are not available. METHODS Prospective clinical evaluation and case report. METHODS In Vitro Fertilization Unit, Herzliya Medical Centers, Herzliya-on-Sea, Israel. METHODS Thirteen couples with male factor infertility in which the male partner lacked spermatozoa in the ejaculate or testicular biopsy samples. METHODS Round spermatid injection and elongated spermatid injection into oocytes. METHODS Evaluation of the rate of two-pronucleated and single-nucleated zygote development. RESULTS The rate of two-pronucleated zygote development after round spermatid injection and elongated spermatid injection was relatively low (27% and 36%, respectively). Single-nucleated zygotes develop more frequently after round spermatid injection and elongated spermatid injection (35% and 17%, respectively) than after intracytoplasmic sperm injection with mature spermatozoa. A normal pregnancy and childbirth resulted from the transfer of 4 cleaving embryos, each of which developed from a single-nucleated zygote in a round spermatid injection treatment cycle with ejaculated spermatids. CONCLUSIONS Embryos derived from single-nucleated zygotes after spermatid conception can be viable and give rise to an ongoing clinical pregnancy and childbirth.