Abstract

The key for human IVF using the intracytoplasmic sperm injection (ICSI) procedure is to find moving and living sperm in azoospermic men. The objective of this study was to determine the effect of induced sperm motility on the fertilization and implantation rates in humans. Testicular sperm extraction (TESE) medium containing sperm stimulators and nutritional elements is specially designed for male factor and/or poor quality sperm with lower motility. Men with obstructed or absent ejaculatory ducts were treated by using a microepididymal sperm aspiration (MESA) procedure. Sperm are aspirated directly from the epididymis for use in the ICSI procedure. Men with non-obstructive azoospermia were treated by using the TESE procedure. Small samples of testicular tissue are obtained by needle or microsurgical biopsy and a few sperm are painstakingly dissected out of the tissue for use in the ICSI procedure. Sperm specimens either from epididymis or testis were divided into the two respective groups. In Group I, the specimens were washed in a TESE medium plus 10% human serum albumin (HSA), and then incubated with TESE medium containing 10% HSA in a 5% CO₂ incubator to induce sperm motility. In Group II, the specimens were washed in human tubal fluid (HTF) medium plus 10% HSA, and then incubated with HTF containing 10% HSA in a 5% CO₂ incubator. After 1 h of incubation, the motility of spermatozoa was evaluated under a microscope. The ICSI procedure was performed under an inverted microscope. Fertilized eggs were cultured in HTF medium containing 10% serum substitute supplement (SSS) until Day 3 for embryo transfer. Patients' pregnancy was followed after embryo transfer. This study demonstrated that incubation of spermatozoa from MESA and TESE procedures in TESE medium, as compared with HTF medium, results in significantly increased sperm progression (MESA sperm: 2-3 vs. 0-1; TESE sperm: 1-1.5 vs. 0-0.1) and motility (MESA sperm: 12.0 ± 1.8% vs. 3.3 ± 0.5%; TESE sperm: 4.5 ± 0.2% vs. 0.15 ± 0.02%) all respectively. Induced motility of spermatozoa in TESE medium, as compared with HTF medium, is associated with a significantly increased fertilization rate (MESA sperm: 74.5 ± 3.5% vs. 60.2 ± 3.1; TESE sperm: 73 ± 4.3% vs. 48.4 ± 3.7%) and implantation rate (MESA sperm: 29.8 ± 3.8% vs. 19.4 ± 2.7%, for patient age 32 ± 3.0, in Group I, n = 13, and in Group II, n = 12; TESE sperm: 23.2 ± 3.3% vs. 15.4 ± 2.8%, patient age 33 ± 2.8%, in Group I, n = 11, and in Group II, n = 9), and significantly decreased the ICSI performing time (30 ± 10 vs. 120 ± 20 min), all respectively. TESE medium can significantly increase the motility of spermatozoa from TESE/MESA, because it contains specific sperm stimulators and nutritional elements that directly resulted in the increase of fertilization and implantation rates.