The outcomes of intracytoplasmic sperm injection (ICSI) using spermatozoa with Y chromosome microdeletion

Abstract

AZF microdeletions are the leading genetic cause of male infertility and useful to obtain reliable genetic information for assisted reproductive techniques. Thus, the detection is clinically relevant for appropriate genetic counseling. However, there are only a few reports evaluating clinical course of the patients with AZF microdeletions. The aim of this study was to clarify the results of microdissection testicular sperm extraction (micro TESE) with Y chromosome microdeletion and ICSI outcomes using sperm from those men. A retrospective study in 18 Japanese reproductive center. This study was retrospectively examined a total of 1934 azoospermic or severe oligozoospermic patinets who undergone genetic testing for AZF deletions in 18 Japanese medical centers from April 2007 to June 2016. We examined genetic testing for AZF deletions by Promega Y Chromosome AZF Analysis System (version 2.0). We firstly investigated each type of AZF deletions frequencies, and sperm retrieval rate (SRR) by micro TESE of the azoospermic patients with AZF deletions. In addition, we analyzed the ICSI results using testicular or ejaculatory sperm of men with AZF deletions. AZF microdeletions were found in 189 cases (9.8%): 20 AZFa, 15 AZFb, 72 AZFc, 1 AZF a+b, 58 AZFb+c, and 23 AZFa+b+c. Of men with isolated AZFc deletion, spermatozoa were retrieved in 71.4% (30/42) by micro TESE. We could not find spermatozoa from patients with other AZF deletions. Twenty-nine couples underwent ICSI using testicular sperm retrieved by micro TESE, and 3 couples underwent ICSI using ejaculatory sperm. In totally, 572 metaphase 2 oocytes were retrieved by 62 oocyte retrieval cycles. Fertilization rate was 46.1% (220/477). We performed 62 embryo transfer (ET) cycles, mean replaced embryos were 1.39 per ET. Implantation rate per total transfer embryos were 19.8% (17/86), and clinical pregnancy rate per ET cycles were 27.4% (17/62). Abortion rate was 23.5% (4/17). Although we could not detect significant differences, the results of ICSI using ejaculatory sperm had better propensity in fertilization rate, implantation rate, and clinical pregnancy rate compared with the results of ICSI using testicular sperm (72.7% vs 44.1%, 50.0% vs 17.5%, 75.0% vs 24.1%, respectively). AZFc deletions are associated with severe dysregulations of spermatogenesis, however, sperm retrieval is possible in more than half by micro-TESE. It is useful to obtain reliable genetic information from azoospermic patients and to avoid unnecessary micro TESE. The results of this study provide useful actual clinical information for infertile couples with AZF deletions.