Very low sperm count affects the result of intracytoplasmic sperm injection

Purpose: The aim was to examine the influence of extremely low sperm count on intracytoplasmic sperm injection (ICSI) outcome. Methods: Over 1000 consecutive unselected ICSI cycles were divided into four groups according to sperm concentration of their patients: A, cryptozoospermia, 107 patients; B, sperm concentration of ≤ 1 x 10⁴, 146 patients; C, sperm count of 1 x 10⁴-1 x 10⁵, 135 patients; and concentration of > 1 x 10⁵ and < 10 x 10⁶/ml (control group), 688 patients. Results: A significant decrease in pregnancy rate was noticed in the cryptozoospermic group in comparison to the control group (20% vs. 31%). Fertilization rate in group A was significantly lower in comparison to all other groups, respectively (46% vs. 52%, 54%, 61%). Embryo quality was inferior in group A in comparison to the control group. A higher yet not statistically significant abortion rate was observed in the cryptozoospermic group (as well as in group C) (30%, 27%) compared to the control group (15%). Conclusions: It seems that an extremely low sperm count has a negative effect on the outcome of ICSI. Nevertheless patients with cryptozoospermia should not be offered ICSI treatment with the ejaculated sperm before karyotype is established.