Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.
"When the initial sample is of very poor quality or with very small number of cells, small cell-number or single cell cryopreservation techniques may become useful. Starting in the late 1990's (Cohen & Garrisi, 1997; Cohen et al., 1997), reports on several single sperm cryopreservation techniques showed up in the scientific literature (Walmsley et al., 1998; Gil-Salom et al., 2000; Gvakharia & Adamson, 2001; Just et al., 2004; Herrler et al., 2006; Isaev et al., 2007; Koscinski et al., 2007; Woods et al., 2010). Using these various techniques, researchers reported a wide range of outcomes and recovery efficiency. "
"A summary of published reports addressing freezing spermatozoa (ejaculated or surgically retrieved) in microquantities or small numbers was presented (Tables II and III). The quantity of cryopreserved sperm was noted in 20 reports (12 full studies and 8 abstracts) (Cohen et al., 1997; Walmsley et al., 1998; Montag et al., 1999; Suzuki et al., 1999; Borini et al., 2000; Liu et al., 2000; Quintans et al., 2000; Hsieh et al., 2000a; Fusi et al., 2001; Gvakharia and Adamson, 2001; Bouamama et al., 2003; Cesana et al., 2003; Levi-Setti et al., 2003; Sohn et al., 2003; Just et al., 2004; Desai et al., 2004a, b; Hassa et al., 2006; Isaev et al., 2007; Sereni et al., 2008) (Table II), whereas in the remaining studies, the number of cryopreserved spermatozoa was not known (Table III). Eleven of the studies documented sperm function by fertilization/cleavage data (Cohen et al., 1997; Walmsley et al., 1998; Borini et al., 2000; Gil-Salom et al., 2000; Fusi et al., 2001; Nawroth et al., 2002; Desai et al., 2004a, b; Isachenko et al., 2004b; Koscinski et al., 2007; Sereni et al., 2008). "
[Show abstract][Hide abstract] ABSTRACT: Despite interest in cryopreservation of individual or small number of human spermatozoa, to date, little data is available as regards its effectiveness. We systematically reviewed the outcome after cryopreservation of individual or small numbers of human spermatozoa in patients with severe male factor of infertility.
We searched the MEDLINE, EMBASE, Cochrane Systematic Reviews, CENTRAL, Web of Science, Scopus databases for relevant studies up to June of 2008. The search used terms referring to cryopreservation of small amount of sperm. Included studies were limited to human studies with no language restrictions.
We identified 30 reports including 9 carriers used for cryopreservation of small quantities/numbers of human spermatozoa (7 non-biological and 2 biological carriers). A wide variety of cryopreservation vehicles were reported. The recovery rate of spermatozoa cryopreserved in a known small number varied widely from 59 to 100%. Fertilization rates were in the range of 18-67%. Frozen-thawed spermatozoa, using this method, were subsequently used for intracytoplasmic sperm injection in only five studies, with few pregnancies reported so far. To date, there remains no consensus as to the ideal carrier for cryopreservation of small number of spermatozoa for clinical purposes.
Cryopreservation of individual or small numbers of human spermatozoa may replace the need for repeated surgical sperm retrieval. A controlled multicenter trial with sufficient follow-up would provide valid evidence of the potential benefit of this approach.
Human Reproduction Update 01/2009; 15(2):153-64. DOI:10.1093/humupd/dmn061 · 10.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study is to develop a novel method for the cryopreservation and efficient post-thaw recovery of individual or small numbers of human spermatozoa. Spermatozoa equilibrated in cryoprotectant buffer were injected with an intracytoplasmic sperm injection (ICSI) needle into a droplet of cryoprotectant on a homemade cryoleaf. The droplet was of cryoprotectant and seminal plasma at a ratio of 1:1. The sperm-loaded cryoleaf was slowly lowered over and stored in liquid nitrogen. Spermatozoa were thawed in a 37°C oil bath without dilution and centrifugation. To test the fertilizing ability of these spermatozoa, the recovered spermatozoa were injected by ICSI into 1-d-old or in vitro-matured human oocytes. Fresh spermatozoa from the same semen samples served as controls. The trials were performed in two separate experiments. In the first set of experiments, 92 spermatozoa were thawed and carefully investigated. The spermatozoa from percutaneous epididymal sperm aspiration had a motility recovery of 92.9% (13/14); ejaculated spermatozoa had a motility recovery of 61.5% (48/78), and only 1.3% (1/78) was lost. Together in the first and second set of experiments, the fertilization rates for the fresh and frozen-thawed spermatozoa were 67.6% (25/37) and 60.6% (40/66), respectively (P = 0.052). The mean embryo cleavage rates in the fresh and frozen-thawed groups were 88% (22/25) and 85% (34/40), respectively (P = 0.990). This cryopreservation method for individual or small numbers of human spermatozoa was efficient and simple. These findings make this method a promising technique for the clinical application of ejaculated sperm from oligozoospermic patients.