A sperm is consisting of 3 parts:
- Head: The head of sperm contains nucleus. The acrosome inside the head of sperm cells stores an enzyme which is important for fertilization when penetrate into the female’s egg.
- Midpiece: It contains a lot of mitochondria that provide energy for sperm motility.
- Tail: Tail is making sperm cells to be able to swim and controlling the direction while moving as well.
There are many types of abnormal sperm morphology, such as the head of sperm is too big or too small, sperm with broken neck, cytoplasmic droplet found at the neck of sperm, sperm with abnormal tail, such as coiled-tail sperm, multiple tails sperm or tail-less sperm.
Any type of abnormal sperm morphology can affect fertility. It reduces the ability to fertilize. It also causes low embryo quality, slow-growing embryo, a decrease of pregnancy rate, and an increase of risk of miscarriage.
Reference: https://www.primefertilitycenter.com/en/how-is-sperm-morphology-important/