Description
Androstenedione (often abbreviated as A4) is an androgen, a type of sex hormone. It is classified as a “prohormone” because the body primarily uses it as a stepping stone to create more powerful hormones: testosterone (a male sex hormone) and estrone (a type of estrogen, a female sex hormone). In females, it is produced in roughly equal amounts by the adrenal glands and the ovaries. In males, it is produced by the adrenal glands and the testes. Measuring A4 levels helps doctors pinpoint imbalances in this complex hormone production pathway.
Clinical Significance:
Investigating Hyperandrogenism: In women, elevated Androstenedione is a key indicator of excess male sex hormones. It helps differentiate whether the excess hormones are originating from the adrenal glands or the ovaries.
Polycystic Ovary Syndrome (PCOS): A4 levels are frequently elevated in women with PCOS, making it an important diagnostic marker alongside testosterone and DHEA-S.
Congenital Adrenal Hyperplasia (CAH): This is a group of genetic disorders affecting the adrenal glands. A4 testing is used to help diagnose CAH and to actively monitor the effectiveness of glucocorticoid replacement therapy in patients already diagnosed.
Adrenal or Gonadal Tumors: Very high levels can sometimes indicate the presence of an androgen-secreting tumor in the adrenal glands, ovaries, or testes.
When is this test recommended?
Healthcare providers typically order an Androstenedione test when a patient presents with:
In Women: Symptoms of virilization or excess androgens, such as excessive facial or body hair (hirsutism), severe acne, male-pattern baldness, irregular menstrual periods, or infertility.
In Men: Symptoms of estrogen excess (since A4 can convert to estrogen), such as breast enlargement (gynecomastia), or during investigations for delayed puberty.
In Infants/Children: If a baby is born with ambiguous genitalia, or if a child shows signs of premature puberty.
Sample Requirements:
Specimen: Blood (Serum).
Container: A standard Gold-top Serum Separator Tube (SST) or a plain Red-top tube.
Patient Preparation:
Time of Day: Because Androstenedione levels fluctuate throughout the day (peaking in the morning), blood is typically drawn early in the day, ideally between 7:00 AM and 10:00 AM.
Menstrual Cycle: For premenopausal women, the doctor may request the test be performed specifically during the week before or the week after a menstrual period, as ovarian A4 production varies throughout the cycle.
Fasting: Some laboratories may require overnight fasting. Patients should verify specific instructions with their healthcare provider.
