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How is semen examined during an evaluation of male infertility?

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Diagram showing the female reproductive system with labeled ovaries, fallopian tubes, uterus, and vagina, alongside hormone pathways and the process from ovulation to fertilization and early embryo development. — infertility Major structures and hormones involved in the initiation of pregnancy. Also seen, at right, is the development of an egg cell (ovum) from follicle to embryo.

A semen analysis is a laboratory examination used to evaluate male infertility. During this process, a sample of seminal fluid is assessed to determine several key factors:1

Volume and Chemistry: The total volume of the semen and its pH level (alkalinity or acidity) are measured.1
Sperm Count and Concentration: The total number of sperm in the ejaculate and the concentration of sperm per cubic centimetre are calculated.12
Motility: The percentage of sperm that are moving effectively is assessed, typically two hours after ejaculation.1
Morphology and Viability: The shape (morphology) and structural health of the sperm are examined under a microscope to ensure they are within normal parameters.12

These microscopic evaluations help identify conditions such as oligospermia (low sperm count) or azoospermia (the complete absence of sperm), which may be caused by obstructions, testicular dysfunction, or other medical issues.2