Conception rates and assisted reproduction in subfertility due to unilateral cryptorchidism.

During 774 spontaneous cycles and 87 cycles of assisted reproduction, the conception rates were evaluated in 48 infertile couples in whom unilateral cryptorchidism was the causal factor. In spite of adjuvant therapy of the male partner, the spontaneous conception rate was very low (1% per cycle). Intra-uterine insemination (IUI) and conventional in vitro fertilization (IVF) resulted in similar success rates of 6.1 and 8.7% per cycle/attempt respectively. After intra-cyto-plasmic sperm injection (ICSI), 46.7% pregnancies were obtained per attempt, and sperm requirements for the latter treatment to be successful were lower than for IUI. It is concluded that subfertility in men with unilateral cryptorchidism is severe, conventional IVF has little advantage, but ICSI is highly successful.