Human Reproduction Unit, Albert Einstein Hospital, Av. Albert Einstein, 627 São Paulo, SP, Brazil; Email: andrea_giannotti{at}hotmail.com
Sir,
We read with interest the article titled Pregnancy with frozen-thawed and fresh testicular biopsy after motile and immotile sperm microinjection, using the mechanical touch technique to assess viability (Oliveira et al., 2004) and we consider it interesting to inform that Human Reproduction readers we have published an article very similar to that one. Our article (Soares et al., 2003
) was titled Sperm tail flexibility test (STFT): a simple test to select viable spermatozoa for ICSI from semen samples without motile spermatozoa. The objective was to describe the results of the injection of immotile spermatozoa with flexible tail when only immotile spermatozoa are present in the semen sample. A retrospective study was conducted to analyze the procedure results for 10 couples who participated in our intracytoplasmic sperm injection program. The sperm tail was considered flexible when it moved up and down independently of the head movement, and it was considered non-flexible when the movement occurred together (tail plus head). The fertilization and pregnancy rates were analyzed. The normal fertilization rate (presence of two pronuclei) was 30.3% (40/132) and the abnormal fertilization rate (presence of less than or more than two pronuclei) was 6.81% (9/132). A total of 52 embryos were obtained with nine transfer procedures performed (pregnancy rate: 11.12%). The sperm tail flexibility test (STFT) is an easy and cost-effective way for selecting viable immotile spermatozoa and can be used as an alternative method for determining the viability of spermatozoa. This test seems to be a simple and risk-free method when compared to the swelling test.
References
de Oliveira NM, Sanchez RV, Fiesta SR, Salgado TL, Rodriguez R, Bethencourt JCA and Zamora RB (2004) Pregnancy with frozen-thawed and fresh testicular biopsy after motile and immotile sperm microinjection, using the mechanical touch technique to assess viability. Hum Reprod 19, 262265.
Soares JB, Glina S, Antunes N, Jr, Wonchockier R, Galuppo AG and Mizrahi FE (2003) Sperm Tail flexibility test: a simple test for selecting viable spermatozoa for intracytoplasmic sperm injection from semen samples without motile spermatozoa. Rev Hosp Clin 58, 250253.