In vitro fertilization outcome in the presence of severe male factor infertility

Abstract

Objective: To assess the outcome of standard IVF treatment (nonmicromanipulated) with respect to total motile sperm number recovered by swim-up, particularly for couples with severe male factor infertility defined as total motile sperm number < 0.5 x 10(6).

Design: Retrospective study of patients who underwent successful oocyte retrieval in an IVF program from August 10, 1992 to December 31, 1993.

Setting: A university-based tertiary referral center (The Toronto Hospital).

Patients: All cycles (n = 672) were divided into four groups according to total motile sperm number recovered using standard swim-up: group 1, total motile sperm number < or = 0.50 x 10(6); group 2, total motile sperm number between 0.51 and 1.00 x 10(6); group 3, total motile sperm number between 1.01 and 1.50 x 10(6); and group 4, total motile sperm number > or = 1.51 x 10(6). All patients received the same controlled ovarian hyperstimulation protocol, which consisted of a GnRH analog flare-up followed by parenteral menotropins. Clinical and cycle characteristics in the four groups were analyzed and outcome was evaluated.

Results: There was no significant difference in clinical and cycle characteristics between the groups. The uniformity of the groups justified analysis of their outcome. A fertilization rate of 21.5% was achieved in couples with severe male factor (group 1). Fertilization rate and number of embryos transferred increased directly with the total motile sperm number. There was no significant difference in implantation rate per embryo between the groups.

Conclusions: The results in couples with severe male factor infertility compare favorably with monospermic fertilization rates reported in the literature using partial zona dissection and subzonal insertion but is lower than with intracytoplasmic sperm injection. Therefore, we believe that couples with severe male factor infertility should be considered for standard IVF, as long as adequate total motile sperm can be recovered (100 x 10(3) per dish). If intracytoplasmic sperm injection is available, it should be offered to these couples.