[Importance of sperm morphology assessment in human in vitro fertilization]

Two hundred eighteen IVF cycles were analyzed in order to clarify the influence of the strictly normal morphology (SNM) of sperm on IVF outcome. SNM was defined according to Kruger et al.'s strict criteria (1988) with our modifications. IVF cycles were divided into 3 groups: %SNM greater than or equal to 40% (69 cycles), 40% less than %SNM greater than or equal to 12% (123 cycles) and %SNM less than 12% (26 cycles). The rates of embryo transfer and pregnancy per cycle and the rate of abortion per pregnancy in the three groups were as follows: 81%, 39%, 19% in %SNM greater than or equal to 40%; 71%, 24%, 30% in 40% greater than %SNM greater than or equal to 12%; and 58%, 7.7%, 50% in %SNM less than 12%. The pregnancy rate per cycle significantly decreased as the %SNM decreased (p less than 0.01), and there was a tendency toward an increase in the abortion rate per pregnancy as the %SNM decreased. The results suggest that %SNM is a useful parameter to use in predicting the IVF outcome.