Human sperm decondensation in vitro is related to cleavage rate and embryo quality in IVF

Abstract

Purpose To investigate whether the ability of human spermatozoa to decondense in vitro in the presence of heparin (Hep) and glutathione (GSH) is related to assisted reproduction (ART) success. Methods Cross-sectional pilot study involving male partners of 129 infertile couples undergoing ICSI with (45) or without (84) donor oocytes at two infertility clinics in CABA, Argentina, between October 2012 and December 2013. In vitro decondensation kinetics with Hep and GSH and DNA fragmentation (TUNEL) were determined on the same sample used for ICSI. The possible relationship of decondensation parameters (maximum decondensation and decondensation velocity) and TUNEL values with ART success was evaluated.Results Embryo quality correlated positively with decondensation velocity (D60/D30) (Spearman's correlation, p < 0.05). According to D60/D30 values, patients were classified as slow decondensers (SlowD) (n = 68) or fast decondensers (FastD) (n = 61). Embryo quality was better in FastD (unpaired t test, p < 0.05). FastD and SlowD were subdivided according to use of donor oocytes. Among SlowD, biochemical and clinical pregnancy rates per transfer were significantly higher in donor (n = 19) vs. in non-donor (n = 31) cycles (Fisher's exact test, p < 0.05). TUNEL values were not related to embryo quality, but no clinical pregnancies or live births were achieved in TUNEL+ SlowD (n = 7). Conclusion Decondensation kinetics of human spermatozoa in vitro with Hep and GSH could be related to embryo quality and ART success.

Unravelling how in vitro capacitation alters ram sperm chromatin before and after cryopreservation

“…17 Recently, the ability of human spermatozoa to decondense in vitro has been related with embryo quality, obtaining better embryo quality when sperm chromatin decondenses faster. 18 This finding highlights the relevance of optimal chromatin decondensation for proper embryo development.…”

“…Furthermore, sperm chromatin must be completely decondensed at the appropriate velocity and time in the fertilization process for successful formation of the male pronucleus and zygote 17 . Recently, the ability of human spermatozoa to decondense in vitro has been related with embryo quality, obtaining better embryo quality when sperm chromatin decondenses faster 18 . This finding highlights the relevance of optimal chromatin decondensation for proper embryo development.…”

PICSI vs. MACS for abnormal sperm DNA fragmentation ICSI cases: a prospective randomized trial

“…The process of fertilization in ICSI includes the following steps: oocyte activation, sperm chromatin de-condensation, sperm Aster formation, syngamy, and ends with mitosis [40]. Sperm chromatin de-condensation plays a vital part in this cascade of events [41]. The process of chromatin decondensation is very much affected by the oocyte's helping mechanisms [42], which are dependent on oocyte's grades of maturity and quality, and are both affected by the maternal age [35,36].…”

Beyond Acephalic Spermatozoa: The Complexity of Intracytoplasmic Sperm Injection Outcomes

“…Both the unique morphology and genetic variation of AS sperm subtypes may affect the development failure in embryos (shown in Table 2 and Figure 1): the complete centrosome/centrioles of the sperm are important for embryonic development [24,50]. Galotto et al [51] and Hart [44] stressed the essential role of sperm centrioles in the early development of the embryo, such as migration of pronuclei, completion of the fertilization, and stimulating the first cleavage of zygote. e development of the embryo requires two centrioles [52].…”