Correlation between oocyte preincubation time and pregnancy rate after intracytoplasmic sperm injection.

BACKGROUND AND AIM: Both nuclear and cytoplasmic maturation of oocytes have to be completed in a coordinated manner to ensure optimal conditions for fertilization. This is well known for in vitro fertilization, but is debated for intracytoplasmic sperm injection (ICSI). It has been reported that preincubation of oocytes prior to ICSI is associated with improved maturation of oocytes, fertilization and embryo quality. Therefore, in the present study, we evaluated the fertilization rate, embryo quality and pregnancy rate in relation to incubation times of metaphase-II oocytes before ICSI. METHOD: We analyzed 135 selected ICSI cycles. Subjects were assigned to six groups according to oocyte incubation time before ICSI: 2-4 h, 5 h, 6 h, 7 h, 8 h and 9-12 h. RESULTS: We observed that the fertilization rate increased slightly at short (2 to 6 h) and then decreased at longer preincubation times (7 to 12 h). Concomitantly, cleavage rate increased up to 6 h of preincubation and decreased significantly in the groups in which ICSI was carried out after 7 to 12 h of incubation. With regard to clinical pregnancy rate, we observed a significant increase from 2 to 5 h of preincubation, when this parameter reached its maximum value (35%), tapering to 33% after 6 h and then dropping sharply to 12 h. CONCLUSIONS: These data confirm that the most appropriate incubation time for mature oocytes before ICSI is 5-6 h. This time improves embryo quality and pregnancy rate in ICSI cycles.

ICSI for treatment of human immunodeficiency virus and hepatitis C virus-serodiscordant couples with infected male partner.

BACKGROUND: Assisted reproductive technology with semen washing can offer a significant reduction in risk of sexual and vertical transmission of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) in serodiscordant couples with infected male partner. METHODS: Among couples coming to our centre for reproductive problems from January 2001 to December 2003, we selected 43 couples with seropositive male and seronegative female: 25 couples with HIV-seropositive males, 10 couples with HIV/hepatitis C virus (HCV)-seropositive males and eight couples with HCV-seropositive males. Sperm samples were washed and used for ICSI. RESULTS: Seventy-eight cycles of ICSI were performed. The mean fertilization rate was 70.34 +/- 20.14% (mean +/- SD). A mean number of 3.55 +/- 1.11 (range: 1-5) embryos of good quality was transferred for each patient. We obtained 22 pregnancies (21 singletons and one twin), with a pregnancy rate per transfer of 28.2% and an implantation rate per transfer of 15.2%. The cumulative pregnancy rate was 51.2%. At follow-up, no seroconversion was detected in any patient. CONCLUSIONS: Our data suggest that sperm wash and ICSI could be useful for reducing the risk of HIV and/or HCV transmission in serodiscordant couples with infected male wishing to have a child, irrespective of their fertility status.