O-146: The clinical impact associated with the use of PICSI TM - derived embryos

Abstract

Oligozoospermic men requiring intracytoplasmic sperm injection (ICSI) often carry seminal populations demonstrating increased levels of chromosomal aberrations and compromised DNA integrity. The in vitro selection of sperm for ICSI is critical and directly influences the paternal contribution to preimplantation embryogenesis. Hyaluronan (H) is a major constituent of the cumulus oophorous matrix and may play a critical role in the selection of functionally competent sperm during in vivo fertilization. Research has demonstrated that H-bound (HB) sperm carry enhanced levels of developmental maturity, sperm chromatin integrity and normal morphology. HB-sperm may contain increased levels of functional competence. The PICSI ™ plate provides microdrops of H for sperm selection and was used in the study. The pilot study examined the use of HB-sperm in the treatment of ICSI patients. 26 ICSI patients were consented for the IRB-approved study and randomized as to their treatment group. ICSI patients in Group A (ICSI or control) received embryos created using standard sperm selection criteria. Group B (PICSI) patients received PICSI embryos created using HB-sperm and Group C (PICSI + ICSI) patients received control and PICSI embryos. 147 and 126 oocytes received sperm selected using the conventional criteria and HB-sperm, respectively. Resulting embryos (n=177) were scored by two independent embryologists. Oocytes of Group A patients received ICSI using sperm selected via the evaluation of motility and morphology. HB-sperm meeting the same criteria were used in the ICSI of Group B oocytes. In Group C, one-half of the oocytes received sperm selected via standard criteria and the other half received HB-sperm. Embryos were assessed on Days 1, 3, 5 and 6 for morphology. Selection for embryo transfer (ET) was based upon morphological criteria. Statistical significance was tested by the Pearson Chi-Squared Statistic using SPSS for Windows. The fertilization rate carried by the PICSI oocytes (61.1%, n=126) was not statistically different (p = 0.071) from that of the control ICSI oocytes (66.6%, n=147). There were no statistically significant differences observed in zygote, embryo and blastocyst morphologies. Differences in the blastocyst conversion rate were not statistically significant (Group A: 53.2%, B: 52.4%, C: 51.9%, p=0.081). The clinical pregnancy rate (CPR) for Group A patients (25.0%, n=8) was statistically lower than that in B (57.1%, n=7) and in C (57.1%, n=7). The CPR of Groups B and C were statistically greater than the non-study ICSI patients during the same time period (33.3%, n=24). Miscarriage rates (MR) were statistically greater in Group A (p=0.013). The current study suggests that the use of H in sperm selection may enhance our ability to isolate optimal sperm from a compromised seminal population. HB-sperm carry a reduced frequency of chromosomal aneuploidy and may exert a positive paternal influence on preimplantation embryogenesis. Patients receiving PICSI-derived or a combination of PICSI and ICSI embryos demonstrated statistically greater CPR and lower MR over those patients receiving only ICSI embryos. Although the study is in its early stages, the increased CPR and reduced MR associated with the use of HB-sperm in ICSI is promising. The study is being continued to further explore the enhanced embryonic potential demonstrated by PICSI-derived embryos.