Oligospermia or oligozoospermia is one of the main causes of male infertility and is a condition when the semen has a lower concentration of sperm than normal. Low sperm concentration or count could mean any amount less than 20 million sperm/ml. Very often, low concentration of sperm also means decreased sperm morphology or motility.

Oligospermia can be caused due to many factors. These include poor health, aging, testicular trauma, varicocele, chemotherapy or radiation. Depending on the cause, the candidate will be started on a supplemental hormone regime to help improve quality of sperm, before undergoing an In-Vitro Fertilization (IVF) /Intracytoplasmic Sperm Injection (ICSI) treatment cycle.