Oligozoospermia

Oligozoospermia means the sperm concentration in an ejaculate is lower than the reference range used by the laboratory, most often the World Health Organization values. It ranges from mild to severe and can result from hormonal causes, varicocele, infection, genetic factors, heat or toxin exposure, certain medicines, or lifestyle factors, though a specific cause is not always found. Because sperm concentration varies naturally between samples, a repeat test is usually recommended before further evaluation. Many men with oligozoospermia can still conceive naturally, with timed intercourse guidance, or with assisted treatments such as IUI, IVF or ICSI depending on the degree and any associated findings.

Also known as: low sperm count, oligospermia

Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.