What a Semen Analysis Measures
Male factor infertility plays a role in about 20 percent of fertility problems. To assess whether there may be a male factor affecting your fertility, your physician will probably recommend a semen analysis. Because a man’s semen consistency and sperm count can vary from day to day, some doctors may recommend that a semen analysis be performed on at least two samples, at least seven days apart, over a period of two to three months.
A semen analysis usually measures:
- Semen volume and pH
- Microscopic evaluation of:
- Sperm concentration
- Sperm morphology (size, shape and appearance)
- Sperm motility (movement)
- Debris found in sperm
- Leukocyte count (white blood cells that could signify infection or other problems)
- Immature germ cells (non-sperm round cells that may be found in semen)
Low sperm volume could be due to an incomplete collection or partial retrograde ejaculation where semen enters the bladder rather than exiting through the urethra during ejaculation. In this case, a repeat semen sample is collected after emptying the bladder. Patients with both low volume and low sperm concentration may be experiencing testosterone deficiency. Less frequently, a low volume with either no sperm (azoospermia) or severely low sperm (severe oligospermia) may suggest some sort of obstruction. A normal volume of semen is at least 1.5mL.
The sperm count of fewer than 15 million sperm per mL is considered low –– the normal range is between 15 million and 200 million sperm per mL. Sperm concentration isn’t totally predictive; men with a lower concentration may be fertile, while men with a higher concentration may still be subfertile. For those with severely low sperm concentration, genetic testing, like karyotyping, may be recommended to help detect any chromosomal abnormalities.
A morphology analysis is performed to study the size, shape, and appearance of sperm. Healthy sperm has oval heads and long tails, which allow them to propel forward. Only 4 percent of sperm need to be normal for a man to be fertile.
Because sperm must propel itself to reach the egg, sperm movement is analyzed, but generally, unless all sperm in the ejaculate are poor movers, motility is not an important factor in predicting male infertility. Experts say the lower limit of normal total motility is 40 percent.
Assisted Reproductive Technology May Help with Male Factor Infertility
Your provider will review the results of the semen analysis with you, and depending on what they discover, they may suggest a second semen analysis, as things can change between samples. In some cases, your fertility doctor may refer you to a reproductive urologist for diagnostic evaluation and potential treatment of male factor infertility. Depending on the cause, assisted reproductive technology may be needed. Methods to increase the odds of conceiving include first-line treatments such as intrauterine insemination (IUI) and more advanced technologies such as in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI).