Does in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) compensate for impaired sperm function as predicted by the sperm penetration assay (SPA)?

Abstract

Objective: The SPA evaluates aspects of the ability of sperm to complete certain processes necessary to achieve fertilization using zona-free hamster oocytes. There has been controversy regarding the correlation between the ability to penetrate zona-free hamster oocytes and fertilization of human oocytes. It is unknown if the fertilization process is the only factor impaired with abnormal SPA tests. The Sperm Capacitation Index (SCI) is the number of sperm penetrations per hamster oocyte. Our objectives were 1) to determine if the SCI has a relationship with implantation rates in IVF with ICSI and 2) to determine if the SCI has a relationship with ongoing pregnancy rates in IVF with ICSI. Design: A retrospective study comparing the outcome of IVF with ICSI from January 1998 to December 2000 in patients with an impaired SCI was performed. All SPAs were performed by Baylor College of Medicine, Houston, Texas. Materials/Methods: The data consisted of 141 oocyte retrieval cycles in which patients had an impaired SCI. An SCI of 5 or less was considered possibly impaired. Exclusion criteria were testicular biopsy and cryobanking cycles. IVF with ICSI was carried out by conventional methods. Chi-square analysis was used to test for differences between SCI groups. Results: Patients were grouped according to SCI: <1, 1–<4, and 4–5. The ongoing clinical pregnancy plus delivery rate (OCPD) per retrieval was 13%, 24%, and 53% respectively. Patients with an SCI of 4–5 had a significantly higher OCPD as compared to the remaining groups. The implantation rate (IR) was also significantly higher for the SCI 4–5 group as compared to the other groups. A trend towards a further reduction in OCPD and IR was noted for patients greater than age 34 with an SCI <4, as compared to patients age <35. Of note, the fertilization rate with ICSI was not significantly different based on SCI result. ∗SPA SCI<11–<44–5Oocyte retrievals (#)537117Clinical pregnancy rate (%)19∗= p < 0.005;28∧= p < 0.05.59∗= p < 0.005;, ∧= p < 0.05.Implantation rate (%)12∗= p < 0.005;18∼= p < 0.005;38∗= p < 0.005;, ∼= p < 0.005;Delivery plus ongoing pregnancies (#)7179Delivery plus ongoing clinical pregnancy rate per retrieval (%)13∗= p < 0.005;24∧= p < 0.05.53∗= p < 0.005;, ∧= p < 0.05.∗ = p < 0.005;∼ = p < 0.005;∧ = p < 0.05. Open table in a new tab Conclusions: Impaired SPA is a good predictor of IVF with ICSI outcome. Patients with an impaired SCI of <4 have a significantly decreased implantation rate and significantly decreased rate of ongoing clinical pregnancy plus delivery following IVF with ICSI. Routine screening of SCI is indicated for pregnancy rate prediction for patients undergoing IVF. Future treatment for patients in whom the SPA is impaired, especially when SCI < 1, may include ovulation induction with intrauterine insemination prior to IVF with ICSI or increasing the number of embryos transferred during IVF with ICSI.