Freezing Sperm a Viable Option in Azoospermic Men

Ricki Lewis, PhD

August 12, 2013

Sperm that are removed from the testicles of men with azoospermia and then frozen are more effective at fertilization than fresh sperm from biopsies, according to a study published online July 29 in PLoS ONE.

Men with azoospermia resulting from an inherited condition, cancer or its treatment, or malfunction or injury of the testicles may become fathers using in vitro fertilization (IVF) if sperm are removed by biopsy and introduced into the ovum via intracytoplasmic sperm injection. Harvested sperm are either used immediately or frozen.

Kenan Omurtag, MD, from the Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Washington University, St Louis, Missouri, and colleagues analyzed intracytoplasmic sperm injection data from 1995 through 2009 from their institution's Infertility and Reproductive Medicine Center. They collected data from 130 men (136 retrievals) undergoing testicular sperm extraction, representing 76 couples undergoing 123 IVF procedures.

Sixty of the men had obstructive azoospermia (congenital absence of the vas deferens, vasectomy, or failed vasectomy reversal), nonobstructive azoospermia, cancer, paralysis, or other causes. Outcomes were successful sperm recovery (1 - 2 sperm per 0.5 mL), fertilization, and delivery of an infant.

The study also evaluated place of sperm retrieval and distance from the IVF laboratory. The biopsies were performed in an operating room next door to the IVF lab, in a building three quarters of a mile away, and at an ambulatory surgical center 15 miles away. Patients transported the specimens from the farthest site, maintained at body temperature, to the laboratory.

Eighty-four percent of the participants used frozen sperm, and the rest used fresh sperm. Although the researchers found no difference in delivery rate, a statistically significant difference emerged in fertilization rate between frozen (62%) and fresh (47%) sperm (P = .0003).

Testicular sperm recovery rate was 70% among patients with cancer and 100% among men with obstructive azoospermia, paralysis, and other causes of infertility. However, only 31% of men with nonobstructive azoospermia had successful recovery, presumably because of their inability to manufacture viable sperm.

Fertilization rate was greater in men with obstructive azoospermia compared with those with nonobstructive azoospermia (66% vs 43%; P < .0001). Rates of clinical pregnancy were similar among the diagnostic groups. Men with obstructive azoospermia had higher delivery rates per cycle (38%) compared with the rates for men with cancer, paralysis, or other conditions (16.7%).

The study also revealed that the type of facility in which men donate sperm and the distance from the IVF laboratory do not affect recovery rate.

The researchers conclude that testicular sperm extraction is safe and effective, irrespective of azoospermia cause, but is more successful in men with obstructive azoospermia.

The authors have disclosed no relevant financial relationships.

PLoS ONE. Published online July 29, 2013. Full text


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