PREGNANCY AND BIRTH AFTER TRANSFER OF EMBRYOS THAT DEVELOPED FROM SINGLE-NUCLEATED ZYGOTES OBTAINED BY INJECTION OF ROUND SPERMATIDS INTO OOCYTES

Objective: To use injection of spermatids into oocytes as a mode of in fertility treatment in cases in which spermatozoa are not available. D esign: Prospective clinical evaluation and case report Setting: In Vit ro Fertilization Unit, Herzliya Medical Centers, Herzliya-on-Sea, Isra el. Patient(s): Thirteen couples with male factor infertility in which the male partner lacked spermatozoa in the ejaculate or testicular bi opsy samples. Intervention(s): Round spermatid injection and elongated spermatid injection into oocytes. Main Outcome Measure(s): Evaluation of the rate of two-pronucleated and single-nucleated zygote developme nt. Result(s): The rate of two-pronucleated zygote development after r ound spermatid injection and elongated spermatid injection was relativ ely low (27% and 36%, respectively). Single-nucleated zygotes develop more frequently after round spermatid injection and elongated spermati d injection (35% and 17%, respectively) than after intracytoplasmic sp erm injection with mature spermatozoa. A normal pregnancy and childbir th resulted from the transfer of 4 cleaving embryos, each of which dev eloped from a single-nucleated zygote in a round spermatid injection t reatment cycle with ejaculated spermatids. Conclusion(s): Embryos deri ved from single-nucleated zygotes after spermatid conception can be vi able and give rise to an ongoing clinical pregnancy and childbirth. (F ertil Steril(R) 1998;70:67-70. (C)1998 by American Society for Reprodu ctive Medicine.).