What it measures
The share of sperm swimming forwards, in a straight line or a large circle. Forward movement is what carries sperm towards the egg.
Why people test it
- Checked by couples who have been trying for a baby for a while.
- Part of a semen analysis, read alongside count, shape and volume.
Typical range
Reported as a percentage of the sperm counted. Labs usually compare it with World Health Organization reference values; ranges vary by lab, and the report shows the lab's own.
Finger-prick or vein?
A semen sample rather than blood, produced at home into the pot from the kit and posted to the lab. Sperm movement changes with time and temperature once the sample is produced, so the kit's timing instructions matter.
Labs ask for a set number of days without ejaculation before the sample, as this affects the result; the kit instructions give the window.