If the condom is a spermicidal condom, the sperm are quickly inactivated. In one study, the percentage of mobile sperm in spermicidal condoms was 10.3% at 30 seconds, 4.3% at 60 seconds, and 1.5% at 120 seconds after ejaculation. In regular condoms, the percentage of mobile sperm was 55.5% at 30 seconds, 52.3% at 30 seconds, 52.3% at 60 seconds, and 50.2% at 120 seconds.