The typical sperm count ranges between 40 and 300 million sperm per milliliter (ml). A doctor will ask a person to ejaculate into a specimen cup to examine their sperm count. They will send this specimen to a laboratory, where technicians will analyze it for sperm count and other characteristics. Men should avoid ejaculating below 25 million sperm per ml because there may be some benefit to men who produce low numbers of high-quality sperm. Women can normally become pregnant with as few as 20 million sperm. For women to become pregnant with fewer than 20 million sperm, all of them must be viable. If any are not viable, then they will be lost when the woman sheds her uterine lining during menstruation. Women are usually aware when they have been pregnant because they feel pain when they shed their uterine lining. If they do not shed the lining of their uterus, it can lead to serious complications for the woman, such as infertility or miscarriage. Many factors can affect a man's sperm count including his age, whether he is genetically prone to low sperm counts, if he takes certain medications, and if he has a history of sexual abuse. Smoking, drinking alcohol excessively, using drugs, and having a partner who uses these methods as well can all decrease a man's sperm count over time. In general, younger men have higher sperm counts than older men because they have not yet reached their maximum potential number of sperm.