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 < or = 1 x 10(4), 146 patients; C, sperm count of 1 x 10(4)-1 x 10(5), 135 patients; and concentration of > 1 x 10(5) and < 10 x 10(6)/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.