Low sperm count means that the fluid (semen) you ejaculate during an orgasm contains fewer sperm than normal. A low sperm count is also called oligospermia. A complete absence of sperm is called azoospermia. Your sperm count is considered lower than normal if you have fewer than 15 million sperm per milliliter of semen.
Having a low sperm count decreases the odds that one of your sperm will fertilize your partners egg, resulting in pregnancy. Nonetheless, many men who have a low sperm count are still able to father a child.
The main sign of low sperm count is the inability to conceive a child. There might be no other obvious signs or symptoms. In some cases, an underlying problem such as an inherited chromosomal abnormality, a hormonal imbalance, dilated testicular veins or a condition that blocks the passage of sperm may cause signs and symptoms.