In this study we examined various techniques of in-vitro fertilization (IVF) for treating couples in whom the male had subnormal semen parameters. We compared two sperm preparation methods (mini-Percoll and conventional swim-up) for efficiency of recovery after preparation and for fertilization rates after IVF, and compared the suitability of partial zona dissection (PZD) and sub-zonal sperm insertion (SUZI) to patients with different types of male factor infertility. The mini-Percoll technique allowed the recovery of significantly more motile spermatozoa from the same semen sample compared to the swim-up method. More oocytes were fertilized after spermatozoa were prepared by the mini-Percoll technique. An increased number of spermatozoa recovered from an ejaculate led to an improvement in the quality of spermatozoa in the insemination droplet. Subsequently, when using the PZD technique, the fertilization rate increased when there was a higher number of spermatozoa in the patient's ejaculate. When comparing the two micromanipulation techniques, SUZI provided patients with oligoasthenzoo-spermia (i.e. < 10 × 106 spermatozoa/ml and 40% motility) with a higher chance of obtaining 2-pronculeate egg
