Sperm abnormal morphology – Teratospermia is a reduced percentage (<4%) of sperm with normal morphology assessed by microscope as part of the routine semen analysis. We are familiar with different types of abnormalities such as tail defects with an impact on sperm swimming capacity or various head abnormalities with a potential detrimental effect on the sperm’s ability to bind and fertilize the egg.
In general, human sperm is highly variable in appearance and the microscopic assessment of sperm morphology is highly subjective and difficult to standardize between laboratories. Only a small proportion (<25%) of the motile sperm from fertile men are capable of binding the egg , and this binding capacity is closely related to the morphology of the sperm head.
Patients need to be reassured that no association exists between sperm abnormal morphology and the risk of fetal abnormality!
Patients with high proportions of sperm with abnormal morphology are now treated successfully by ICSI because of the risk of failure of fertilization with standard IVF. ICSI results are independent of sperm morphology.