Epididymal sperm from the obstructed azoospermic patient: Optimizing pregnancy rates while reducing multiple gestation

Abstract

To explain the higher clinical pregnancy rates /multiple births obtained with intracytoplasmic sperm injection (ICSI) when microsurgical epididymal sperm aspiration (MESA)-derived sperm is used from the obstructed azoospermic patient compared to ejaculated sperm from other infertile males. A secondary objective was to determine the effect of previous cryopreservation of MESA semen samples on ICSI outcomes. Retrospective analysis of male patients who had an ICSI procedure (and their female partners) between January 1997 and December 2003. Semen analysis was performed on MESA specimens at the time of the MESA and post thaw/post-processing. Pre-screening of thawed specimens for use in ICSI was performed. Main outcome measures examined over time and between fresh and frozen MESA samples were fertilization, implantation, pregnancy and multiple birth rates. Pearson Chi-Square tests were used to test for association between ICSI outcome measures and treatment groups. Differences in ICSI outcomes across time were tested using a Poisson Regression Model. The mean number of embryos transferred per cycle was tested over time using analysis of variance (ANOVA). MESA-ICSI cases resulted in higher embryo implantation rates (40% vs. 23.5%) and clinical pregnancy rates (77.5% vs. 40.5%) compared to ICSI cases using mostly ejaculated sperm in the last two years of the study. Cryopreservation of MESA sperm did not reduce pregnancy rates although the number of motile sperm available for the ICSI procedure was markedly reduced. Fertilization rate (p=0.01), implantation rate (p<0.001) and live birth/ongoing pregnancy rate (p=0.02) increased over the study period. The number of embryos transferred over time decreased (p=.011) due to the introduction of blastocyst culture in 1999. Interestingly, the changes in lab procedures, personnel or supplies did not occur coincident with the increase in pregnancy rate observed in 2002. However, more female partners had previous proven fertility in the years 2002 and 2003. High rates of embryo implantation and clinical pregnancy can be expected when MESA sperm from obstructive azospermic men are used for ICSI; especially, if the female partner has had a live born. A reduced number (1–2) of embryos should be transferred when the primary diagnosis of infertility is due to vasal occlusion in order to reduce the incidence of multiple gestation pregnancies in this subgroup of male factor patients.