Not all sperms of a person will look alike. There can be a lot of variations of sperm in the same sample of the man. To test the sperm morphology, the test samples are placed under the microscope and the percentage of sperm that have the normal form or NF is calculated. Experts will calculate the number of NF in 200 sperms in a sample. The analysis can also be done using a computer-aided sperm morphometric assessment (CASA). The latter is considered more precise. A low sperm morphology score is not indicative of infertility.