Although males account for approximately one-third of infertility issues, there is little testing available to determine the cause. The main test for assessing male fertility is the basic semen analysis, which is mainly comprised of determining the sperm count, motility, and morphology. Some labs extend the analysis to include additional tests such as white blood cell counts and anti-sperm antibody assessment.
The morphology assessment of a semen sample aims to determine how “normal” sperm looks. This is done by assessing individual sperm and giving them a characteristic based on their appearance. Most ART laboratories follow the Kruger’s Strict Morphology guidelines in which a normal value is a score of greater or equal to 4% normal.
Anything below 4% is considered abnormal and is given the diagnosis of teratozoospermia. Although it is not uncommon to have a score of less than 4% normal for morphology, the individual sperm characteristics are also very important when physicians are reviewing a patient’s morphology results.
Sperm defects can be characterized as too large, too small, abnormal neck, and abnormal tails, in addition to many others. Some defects are very detrimental to sperm function, while others do not affect the function of sperm.
Sperm morphology is an additional tool used for determining the best course of treatment for a couple. Patients with very low morphology scores are usually recommended to pursue in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI), while slightly abnormal morphology scores may consider intrauterine insemination (IUI) or conventional IVF treatment.