Male fertility
Before IUI, IVF or ICSI the laboratory separates sperm from seminal fluid using density gradient or swim-up methods, concentrating motile sperm and removing debris and prostaglandins. This is why raw semen is never placed directly into the uterus.
Also known as: sperm washing, density gradient, swim-up
Sources
- WHO laboratory manual for the examination and processing of human semen (who.int)
- Royal Australian and New Zealand College of Obstetricians and Gynaecologists (ranzcog.edu.au)
Last reviewed: 10 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.