Effect of heat-induced hypermotility on pregnancy rate in intrauterine insemination for male factor infertility associated with asthenospermia: a prospective, randomized, controlled study.

OBJECTIVE

To assess the effect of mild heat for the enhancement of sperm fertilizing capacity in intrauterine insemination for male factor infertility associated with asthenospermia.

MATERIAL AND METHOD: Prospective, controlled, clinical study. Male factor infertility associated with asthenozoospermia was the criteria for inclusion. Ninety-seven couples were randomized to the study group while 100 couples were randomized to serve as the control group. Semen samples from the study group were processed with Percoll gradient and were left for incubation at 40 degrees C for 2 h. Semen samples from the control group were processed with Percoll gradient method and were incubated at 37 degrees C. Main outcome measure was the pregnancy rate.

RESULTS

The mean concentration of total motile sperm (TMS) in the study group was 11.20 +/- 4.22 x 10(6) (range 7-18) after wash with Percoll while was increased to 62.41 +/- 12.49 x 10(6) (range 44-71) after heat treatment. The mean concentration of TMS in the control group was 13.90 +/- 5.66 x 10(6) (range 8-19) after wash with Percoll while was increased to 17.73 +/- 3.67 x 10(6) (range 14-22) after incubation at 37 degrees C. The difference in TMS concentrations between the study and the control group after incubation at different temperatures was statistically significant (p < 0.005). There were 24 pregnancies in the study group, providing a pregnancy rate of 24.7%. In the control group eight pregnancies were achieved (8%) (p = 0.001).

CONCLUSION

Mild heat was found remarkably effective in asthenozoospermic males for increasing the concentration of inseminated total motile sperm and the pregnancy rate correspondingly.