Most couples undergoing treatment with IVF do not require ICSI. The most common indication for ICSI is male factor infertility associated with an abnormal semen analysis. Therefore, men with unproven fertility whose sperm count, motility, or morphology is suboptimal are appropriate candidates for IVF with ICSI to ensure fertilization of the ova.

Another common indication for ICSI is unexplained infertility. In these couples, neither the man nor the woman has any apparent fertility-related problems. Their diagnostic evaluation is entirely normal, yet infertility exists. In such couples, traditional IVF may result in fertilization failure in 20%–40% of IVF cycles. By using ICSI, the eggs are “forced” to fertilize, and the pregnancy rates are usually high. Fertilization rates with ICSI are usually 60%–80% depending upon egg and sperm factors.