A high DFI score does not preclude patients from achieving a pregnancy with ICSI.
T. A. Elliott, T. H. Taylor, C. A. Jacobs, W. E. Roudebush, W. Brockman, Z. P. Nagy; Reproductive Biology Associates, Atlanta, GA
Objective: The Sperm Chromatin Structure Assay (SCSA), a newly available diagnostic tool for IVF practitioners, measures the percentage of sperm with high levels of DNA fragmentation - DNA Fragmentation Index (% DFI). The results are used to ascertain the fertility potential of patients receiving fertility treatment. The objective of this study was to evaluate the correlation between DFI and outcome in patients receiving ICSI treatment.
Design: A retrospective analysis of 68 IVF patient cycles, between January 2003 and April 2004 with SCSA test results.
Materials and Methods: Patients were included if they received ICSI, a day 3 transfer and did not have pre-implantation genetic diagnosis. Patients were divided into 3 groups depending on DFI score:
* Excellent fertility potential ~ less than 15% DFI (Group I)
* Good fertility potential ~ 15-30% DFI (Group II)
* Poor fertility potential ~ >30% DFI (Group III)
The embryos were scored on day 3 accounting for morphology, cell number, and cell fragmentation, using a grading system whereby 4 is highest quality and 1 is poorest quality. A statistical analysis using one-way ANOVA and CHI-SQUARED test was used to determine any significant trends in rates of fertilization, embryo quality and pregnancy (+hCG) with a P level of 0.05.
Results: Of the total population, 19 patients were in group I, 29 in group II and 20 in group III. Fertilization rates in groups I, II and III were 62.2 (±18.7), 60.9 (±20.8) and 50.7 (±20.7) respectively (P>0.05). Average embryo quality on day 3 in groups I, II and III was 2.83 (±0.82), 2.97 (±0.59) and 2.98 (±0.58) respectively (P>0.05). Pregnancy rates in groups I, II and III were 10/19 (53%), 16/29 (55%) and 9/20 (45%) respectively (P>0.05).
The difference in female age between the 3 groups was not significant; the average age in groups I, II and III was 34.2 (±5.46), 33.9 (±4.75) and 33.95 (±4.40) respectively (P>0.05). The number of embryos transferred between the 3 groups was not significant; the average number transferred in groups I, II and III was 2.74 (±0.93), 2.48 (±0.87) and 3.25 (±1.773) respectively (P>0.05).
Conclusion: This analysis of initial data shows no significant difference between all groups in fertilization rate (although there does seem to be a trend towards decreasing fertilization rate with increasing DFI), embryo quality on day 3 or pregnancy rate. An extension of the present study may be warrented to strengthen the value of these findings by increasing the size of the study groups, and improving standards of protocol, for example performing the SCSA analysis on the day of oocytes retrieval, removing time factors and effects of any treatment (such as anti-oxidant therapy). Most importantly, these results do show that even with a high DFI score, patients can still achieve a pregnancy, including one patient with a DFI of 49 who has an ongoing twin pregnancy.