Infertility Research Today is a free monthly online journal that collates and summarizes the latest research about Infertility, including details on male and female infertility, treatment, causes, pregnancy.

Sperm DNA fragmentation in subfertile men: the effect on the outcome of intracytoplasmic sperm injection and correlation with sperm variables.

Nicopoullos JD, Gilling-Smith C, Almeida PA, Homa S, Norman-Taylor JQ, Ramsay JW

Assisted Conception Unit, Chelsea & Westminster Hospital, London, UK. jnicopoullos@aol.com

OBJECTIVE: To present the first UK data on sperm DNA fragmentation levels in subfertile men and fertile controls, the correlation with semen variables, and to assess the effect on the outcome of intracytoplasmic sperm injection (ICSI). PATIENTS, SUBJECTS AND METHODS: In all, 56 subfertile men undergoing ICSI (28 with positive and 28 with a negative outcome for paternity) and 10 control fertile semen donors were recruited. The sperm DNA fragmentation index (DFI) was assessed on raw pre-preparation samples using the sperm chromatin structure assay. A mean of 5212 sperm were analysed per sample and DFI data are presented by fertility status, ICSI outcome and correlated with semen variables (assessed using World Health Organisation criteria). RESULTS: Total DFI was significantly higher in subfertile men than in fertile controls (mean and median of 22.8% and 17.0% vs 8.4% and 5.0%; P < 0.001), as was the proportion of both moderate DFI (16.4% and 13.0% vs 6.4% and 4.0%; P = 0.001) and high DFI (6.2% and 6.1 vs 2.0% and 1.0%; P = 0.01). This difference remained significant when the control men were compared only with the subfertile men with successful paternity. There was no significant difference in DFI in the subfertile men when analysed by ICSI outcome (mean and median of 24.5% and 17.0% vs 22.3% and 21.0% for successful and unsuccessful cycles, respectively; P = 0.94). There was a positive statistically significant correlation (r = 0.37; P = 0.02) between the DFI and sperm morphology. CONCLUSIONS: This study confirms a relationship between male subfertility and sperm DFI; we discuss the correct role for genetic testing of sperm in the evaluation of subfertile men. Although DNA fragmentation data might help to decide a suitable treatment, once it is decided to proceed with ICSI, DFI levels have no effect on the outcome.

Published 20 May 2008 in BJU Int, 101(12): 1553-60.
Full-text of this article is available online (may require subscription).

© 2004-2008 Infertility Research Today. All Rights Reserved.