Sperm morphology

Sperm morphology assessment looks at the shape of the head, midpiece and tail of sperm under a microscope, usually using strict criteria. Only a minority of sperm in a normal, fertile sample have a perfectly typical shape, so morphology reference values are set accordingly rather than expecting most sperm to look ideal. A low percentage of typically shaped sperm (teratozoospermia) can occur with otherwise normal counts and motility, and often has no single identifiable cause. Morphology is one part of the overall picture used alongside concentration and motility; it does not on its own predict whether natural conception, IUI or IVF/ICSI is likely to work.

Also known as: normal forms, abnormal sperm shape, sperm shape

Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.