Assessing sperm morphology

Spermatozoa morphology is a very good indicator of sperm quality. In our center, spermatozoa morphology assessment is done according to criteria in the “WHO Manual for Examination and Processing of Human Sperm, 5th edition” using “Spermac stain”, which stains the nucleus red and the acrosome, neck and tail green. After staining, spermatozoa morphology is analyzed under a microscope at 100X magnification. Both abnormal and normal forms are recorded and over 200 spermatozoa are evaluated. Thirty-eight distinct types of anomaly in the head, neck and tail of the sperm cell, can be detected. If the ratio of spermatozoa with a normal morphology in a sample is below 4%, this condition is diagnosed as teratozoospermia. Although rates below or above 4% are considered to have some significance with regard to fertilization and pregnancy, every laboratory has to determine its own thresholds. For example, according to Kruger strict criteria, if this value is below 4%, the sub-distribution of anomalies is scrutinized: head anomalies may be severe or mild, affecting fertilization differently. In our center, we consider that severe head defects are significant for the ART outcome. This issue is clarified during counseling.