Optimal time interval for intracytoplasmic sperm injection after administration of human chorionic gonadotrophin in severe male factor infertily.
[P-67] OPTIMAL TIME INTERVAL FOR INTRACYTOPLASMIC SPERM INJECTION AFTER ADMINISTRATION OF HUMAN CHORIONIC GONADOTROPHIN IN SEVERE MALE FACTOR INFERTILITY.
D. Telles Schneider, A. Prado Gomes, S. Verza Jr., S. C. Esteves. ANDROFERT-Centro de Referência em Infertilidade Masculina, Campinas, Brazil
Objetive: Oocyte developmental capacity declines by ~55 hours after hCG administration. In ICSI cycles involving severe male factor cases, especially those dealing with nonobstructive azoospermic men, the time frame between oocyte retrieval and microinjection may be long due to technical difficulties for sperm procurement. The objective of this study was to evaluate the impact of the time for ICSI after hCG administration in severe male factor cases on fertilization and embryo development.
Design: A retrospective study of laboratorial data.
Materials and Methods: A total of 550 ICSI cycles involving 4334 oocytes performed between January 2002 to March 2005 were reviewed. ICSI cycles included only severe male factor cases, and the sperm source for microinjection was as follows: ejaculated (n=364), epidydimal (n=30) and testis (n=75). Injected oocytes were grouped according to the time elapsed between hCG administration and microinjection. Oocytes from a single case may be assigned to different timing groups, such as in the cases that it has taken long to perform ICSI due to technical difficulties to find sperm. Therefore, implantation and pregnancy rates were not analyzed. In addition, the timing of case assignment was random and based only by work load. Normal (2PN) and abnormal fertilization rates, as well as embryo quality on days 2 and 3 were evaluated. Kruskal-Wallis statistic was used for comparisons among groups. Values are expressed as median [25-75 percentiles].
Results: Oocytes injected either earlier than 38h or longer than 43h after hCG administration showed significant decreased fertilization rates and embryo development (table). Oocytes injected between 38 to 42h fertilized and developed as good quality embryos at significantly higher rates than the other time groups. The proportion of oocytes injected with testicular spermatozoa in the group of >43h was significantly higher than the others (table), and we speculated that it may justify the observed decreased fertilization rate and embryo development based on possible male gamete deficiencies. After excluding the oocytes injected with testicular sperm in all groups, we observed that a trend to lower fertilization and embryo development still remained at >43h group, but at non-significant levels. Oocytes matured in vitro and injected on the next day showed significant lower fertilization and embryo development.
| ICSI outcomes according to the time elapsed between hCG administration and microinjection | ||||||
| Injected oocytes (n) | Normal fertilization rates (%) | Abnormal fertilization rates (%) | Good quality embryos on Day 2 (%) | Good quality embryos on Day 3 (%) | Oocytes injected with testicular sperm (%) | |
| Group I (<38h) | 60 | 63 [43-86] | 0 | 47 [0-71] | 7 [0-28] | 0 |
| Group II (38-43h) | 3014 | 73 [50-100] | 0 [0-14] | 65 [33-100] | 50 [0-75] | 26 |
| Group III (>43h) | 1079 | 56 [38-86] | 0 [0-20] | 46 [0-100] | 33 [0-67] | 37 |
| Group IV (day after) | 181 | 44 [0-100] | 0 | 24 [0-50] | na | 18 |
| P-value | — | GIIxGIII: <0.01; GI-IIIxGIV<0.01 | NS | GIxGII <0.01; GIIxGIII<0.01; GI-IIIxGIV <0.001 | GIxGII<0.01; GIIxGIII=0.02 | GIIIxGII/GIV <0.01 |
Conclusion: The optimal time for ICSI in severe male factor infertility cases seems to range from 38 to 42h after hCG administration. One should expect lower fertilization and embryo development with microinjections performed >43h after hCG, especially when using testicular spermatozoa. In such cases, it seems reasonable to schedule the sperm retrieval procedure at early hours on the day of ICSI or at the previous day. Such strategy may be useful to allow microinjections to take place at the optimal window, thus minimizing a possible impairment in the oocyte development due to the quality of the male gamete.