Human Reproduction Vol. 20 No. 3 © The Author 2005; all rights reserved
Reply to: the predictive value of sperm chromatin structure assay
The Fertility Clinic, Viborg Hospital (Skive), Resenvej 25, DK-7800 Skive, Denmark
1 Email: mona.bungum{at}sygehusviborg.dk
Sir,
We thank Nicopoullos et al. (2004)
for their interest in our paper focusing on the predictive value of the sperm chromatin structure assay (SCSA) on the outcome of intrauterine insemination, IVF and ICSI and appreciate the opportunity to adress their comments.
Nicopoullos et al. in their letter point out that the individual DFI values in the 13 pregnancies following IVF or ICSI with a DFI >27% are not specified in our paper. We certainly agree that these data could have been of informative value. The mean DFI level in these 13 pregnancies was 34.2%, ranging from 27.2% to 52.2%.
Secondly Nicopoullos et al. draw attention to their own unpublished work where the findings are well in accordance with our study (Bungum et al., 2004). According to Nicopoullos et al. the only previous study that has assessed the effect of DFI on ICSI cycles alone is the study of Benchaib et al. (2003). This is not correct, however, as the Benchaib paper was based on both IVF and ICSI patients, 50 and 54, respectively. DFI was calculated with the TUNEL technique. Benchaib et al. measured DFI after gradient centrifugation and set a threshold at 10% positivity (low and high DNA fragmentation). With this cut-off value they found significant differences in the ICSI fertilization rate (but not in IVF) and in the percentage of embryos reaching the blastocyst stage. Regarding pregnancy, in the IVF group no differences were seen between high and low DFI. In the ICSI group, however, high DFI was a pejorative factor as no pregnancies were seen when DFI was >20%. There are, however, two other recently published studies using the SCSA in ICSI patients (Gandini et al., 2004; Virro et al., 2004), both concluding that it is possible to obtain high pregnancy rates in couples with high DFI levels.
Finally, Nicopoullos et al. raise the question of whether sperm aneuploidy screening in combination with SCSA can be used as a tool to foresee a couple's chance of success with ICSI. Calogero et al. (2001) using FISH on sperm after swim up for chromosomes X, Y, 8, 12, 18 in 18 ICSI patients found a higher aneuploidy rate in ICSI patients compared to the control group consisting of 13 normospermic men. In patients with lack of pregnancy there was a trend toward higher aneuploidy rates even though pregancies were also obtained in the presence of elevated aneuploidy rates. There is, however, still controversy over whether these analytical techniques are able to identify the level of damage to spermatozoa, and therefore it will be interesting to follow the future research on this issue. As already stated in Bungum et al. (2004), additional large-scale trials in different clinical settings are needed to further investigate the value of SCSA in relation to other available pregnancy predictors in vivo or in vitro.
References
Bungum M, Humaidan P, Spano M, Jepson K, Bungum L and Giwercman A (2004) The predictive value of sperm chromatin structure assay (SCSA) parameters for the outcome of intrauterine insemination, IVF and ICSI. Hum Reprod 19, 1401–1408.
Calogero AE, De Palma A, Grazioso C, Barone N, Burrello N, Palermo I, Gulisano A, Pafumi C and D'Agata R (2001) High sperm aneuploidy rate in unselected infertile patients and its relationship with intracytoplasmic sperm injection outcome. Hum Reprod 16, 1433–1439.
Gandini L, Lombardo F, Paoli D et al. (2004) Full-term pregnancies achieved with ICSI despite high levels of sperm chromatin damage. Hum Reprod 19, 1409–1417.
Nicopoullos J, Gilling-Smith C, Almeida P and Ramsay J (2004) The predictive value of sperm chromatin structure assay. Hum Reprod, In Press.
Virro MR, Kjersten L, Larson-Cook KL and Evenson DP (2004) Sperm chromatin structure assay (SCSA) parameters are related to fertilization, blastocyst development, and ongoing pregnancy in in vitro fertilization and intracytoplamic sperm injection cycles. Fertil Steril 81, 1289–1295.[CrossRef][Web of Science][Medline]
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  D. Evenson Reply to: 'The predictive value of the sperm chromatin structure assay (SCSA)'--a response from the SCSA inventor. Hum. Reprod., February 1, 2006; 21(2): 570 - 572. [Full Text] [PDF]
|
|
|
|
|
|
J. G.Alvarez The predictive value of sperm chromatin structure assay Hum. Reprod., August 1, 2005; 20(8): 2365 - 2367. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||