Infertility affects many couples globally, with male factors contributing to roughly half of all cases. This can stem from issues impacting sperm production, delivery, or function. Evaluating semen quality is a fundamental step in addressing these reproductive challenges, as it provides insights into a man’s fertility potential and helps identify underlying concerns.
Defining Semen Quality
Semen quality is assessed through a semen analysis, a laboratory test that examines several parameters of the ejaculated fluid and the sperm within it. Three main parameters are typically evaluated: sperm concentration, motility, and morphology.
Sperm concentration refers to the number of sperm present per milliliter of semen. A normal range is generally considered to be at least 15 million sperm per milliliter, or 39 million total sperm per ejaculate. A low sperm count is known as oligospermia; the complete absence of sperm is termed azoospermia.
Sperm motility describes the movement of sperm, specifically their ability to swim forward effectively. For fertility, at least 30-32% of sperm should exhibit progressive motility, meaning they move actively and in a straight line. Poor sperm movement is referred to as asthenozoospermia.
Sperm morphology refers to the shape and structure of the sperm. A normal sperm has an oval head and a long tail. According to World Health Organization (WHO) guidelines, a normal sample should contain at least 4% normally shaped sperm. Abnormal sperm shape is called teratozoospermia.
Causes of Poor Semen Quality
Poor semen quality can arise from medical conditions, lifestyle choices, and environmental exposures, each affecting sperm production or transport differently.
Medical Conditions
Varicocele, enlarged veins in the scrotum, is a common correctable cause of male infertility, potentially impacting sperm by increasing testicular temperature. Infections, including sexually transmitted infections or urinary tract infections, can damage sperm production or create blockages. Hormonal imbalances from issues with the hypothalamus, pituitary gland, or testes can disrupt sperm creation.
Undescended testes, physical injury to the testicles, or prior surgeries in the testicular or abdominal area may also affect sperm production or transport. Genetic factors, including Y chromosome microdeletions or conditions like Klinefelter syndrome, can lead to low or no sperm production.
Lifestyle Factors
Obesity can negatively impact sperm parameters, possibly due to hormonal changes or increased scrotal temperature. Habits such as smoking, excessive alcohol consumption, and the use of certain illicit drugs like marijuana or anabolic steroids are associated with reduced sperm count, motility, and increased sperm DNA damage. Prolonged emotional stress can also affect semen quality.
Environmental Exposures
Long-term contact with industrial chemicals, including insecticides, pesticides, and organic solvents, has been linked to lower sperm counts. Exposure to heavy metals like lead or radiation can also impair sperm production, with high doses potentially causing lifelong effects. Additionally, excessive heat exposure to the scrotum, from sources like hot tubs, saunas, or prolonged laptop use, can negatively affect sperm count and function.
The Diagnostic Process
Investigating male infertility begins with a clinical assessment. This includes a medical history, covering past illnesses, surgeries, or exposures that might affect fertility. A physical examination of the genitals helps identify structural issues like varicoceles or testicular abnormalities. Signs of hormonal imbalances, such as changes in body hair or muscle mass, are also noted.
Semen analysis is central to the diagnostic evaluation, providing information on sperm concentration, motility, and morphology. To ensure accurate results, the sample is collected after 2 to 5 days of abstinence. If initial results are abnormal, the test is repeated after several weeks, as sperm parameters can fluctuate.
Further diagnostic steps may include blood tests to assess hormone levels (FSH, LH, testosterone) involved in sperm production. Genetic testing may be recommended for men with very low or absent sperm counts to identify chromosomal abnormalities like Y chromosome microdeletions or Klinefelter syndrome.
Imaging tests, such as a scrotal ultrasound, can help detect varicoceles, testicular issues, or blockages. A post-ejaculate urine analysis may also be performed to check for retrograde ejaculation, where semen enters the bladder instead of exiting the penis.
Treatment and Management Options
Addressing poor semen quality involves a multi-step approach, often beginning with less invasive interventions.
Lifestyle Modifications
Lifestyle modifications are recommended, as they can improve sperm health. Reducing or eliminating smoking, excessive alcohol consumption, and illicit drug use can improve sperm parameters. Maintaining a healthy weight through diet and regular exercise may also enhance hormonal balance and sperm production. Avoiding prolonged heat exposure to the testicles, such as from hot baths or tight clothing, can be beneficial.
Medical Treatments
Medical treatments are available for specific underlying causes. Hormone therapy, using medications like clomiphene citrate or human chorionic gonadotropin (hCG), can stimulate the brain’s glands to increase sperm production when hormonal imbalances are identified. Infections affecting the reproductive tract can be treated with antibiotics.
For men with varicoceles, surgical repair (varicocelectomy) can improve semen quality and potentially lead to natural conception. Surgical procedures can also correct blockages in the sperm transport system, such as a vasectomy reversal.
Assisted Reproductive Technologies (ART)
When other treatments are not effective, assisted reproductive technologies (ART) offer options for conception. In vitro fertilization (IVF) involves fertilizing eggs with sperm in a laboratory setting.
Intracytoplasmic sperm injection (ICSI) is performed alongside IVF, especially for severe male factor infertility. During ICSI, a single sperm is directly injected into an egg, bypassing issues with sperm movement or ability to penetrate the egg. If sperm cannot be obtained through ejaculation, surgical sperm retrieval techniques can extract sperm directly from the testes for use in IVF with ICSI.