The inability to conceive often involves male fertility factors, most commonly a low concentration of sperm in the ejaculate, medically termed oligospermia. This condition significantly reduces the chance of natural conception. Understanding the diagnosis and underlying causes is the first step toward effective solutions. Oligospermia is a primary diagnosis managed through targeted medical and reproductive interventions.
Defining Low Sperm Count and Diagnosis
The formal diagnosis of oligospermia relies on a laboratory test called semen analysis, which provides a detailed microscopic assessment of the ejaculate. The technician assesses several factors, including the volume and pH of the fluid, the percentage of motile sperm, and the proportion of sperm with normal morphology (shape).
The most important measurement for diagnosing oligospermia is sperm concentration, which is the number of sperm present in one milliliter of semen. According to the World Health Organization (WHO) guidelines, a concentration below 15 million sperm per milliliter (million/mL) or a total sperm count below 39 million per ejaculate is considered low. This threshold establishes the presence of oligospermia and often determines the recommended treatment path.
The severity of the condition is categorized to guide clinical decisions. Mild oligospermia is typically defined by a concentration between 10 and 15 million/mL. A moderate classification falls between 5 and 10 million/mL, where natural pregnancy rates are noticeably reduced. Severe oligospermia represents the lowest concentration, below 5 million/mL, often necessitating more advanced assisted reproductive technologies.
Underlying Factors Leading to Oligospermia
The factors contributing to a low sperm count are diverse, ranging from anatomical issues to hormonal imbalances and environmental exposures. One frequently identified correctable physical cause is a varicocele, an enlargement of the veins within the scrotum. This pooling of blood causes the scrotal temperature to rise above the optimal level required for healthy sperm production, impairing spermatogenesis.
Hormonal regulation of sperm production (spermatogenesis) involves a complex feedback loop controlled by the brain and testes. The pituitary gland releases Luteinizing Hormone (LH), which stimulates testosterone production in the testes, essential for sperm maturation. Follicle-Stimulating Hormone (FSH) acts on the Sertoli cells to support developing sperm cells. An imbalance in this axis, such as a deficiency in FSH or LH, can severely disrupt sperm creation.
Structural blockages can also prevent sperm from exiting the body, leading to a low count or, in some cases, no sperm at all. These obstructions, which may occur anywhere from the epididymis to the ejaculatory ducts, are sometimes the result of prior infections, such as sexually transmitted infections. On a genetic level, conditions like Klinefelter syndrome (47, XXY) or Y chromosome microdeletions in the Azoospermia Factor (AZF) region can cause testicular failure and severe spermatogenic impairment.
Environmental and lifestyle factors contribute to reduced sperm count and quality. Obesity can lead to hormonal changes by increasing estrogen levels and lowering testosterone, while also elevating scrotal temperature. Exposure to excessive heat from sources like hot tubs or saunas is detrimental, as are certain medications, including anabolic steroids, some chemotherapy agents, and specific antidepressants.
Addressing Fertility When Oligospermia is Present
When oligospermia is diagnosed, treatment first focuses on correcting any identifiable underlying causes. For instance, a varicocele may be surgically repaired through a varicocelectomy to restore proper blood flow and lower testicular temperature. This intervention can often improve semen parameters enough to allow for a less invasive path to conception.
Hormonal therapies are an option for men with specific imbalances, such as low testosterone and low gonadotropin levels. Clomiphene citrate, used off-label, works by blocking estrogen’s negative feedback on the pituitary gland, increasing the release of LH and FSH. This boost in stimulating hormones can increase endogenous testosterone production and improve sperm concentration.
If an obstruction is the issue, surgical procedures like Transurethral Resection of the Ejaculatory Ducts (TURED) can open blockages. For cases where the sperm count remains low despite corrective measures, or when the cause is untreatable, assisted reproductive technology (ART) offers pathways to pregnancy. Intrauterine Insemination (IUI) is often the first ART step for mild oligospermia, where processed sperm is placed directly into the uterus, bypassing the cervix.
When sperm concentration is moderate to severe, In Vitro Fertilization (IVF) is recommended, allowing fertilization to occur externally in a lab dish. For the most severe cases of oligospermia, or when prior IVF attempts have failed, Intracytoplasmic Sperm Injection (ICSI) is used. ICSI is a specialized procedure where a single, selected sperm is injected directly into the center of the egg, maximizing the chance of fertilization.