Do ovarian androgens support early follicle development and granulosa cell sensitivity to FSH?

In the context of reproductive aging and ovarian physiology, particularly for individuals in their late 30s, the role of androgens has emerged as a critical factor in understanding follicular health and response to stimulation.

Clinical and effectiveness evidence

Androgen levels, including testosterone and dehydroepiandrosterone (DHEA), are closely linked to markers of ovarian reserve and clinical response.

• Response Correlation: Studies categorized by the POSEIDON criteria (specifically group 3, younger women with low reserve) show that significant hypoandrogenemia across serum testosterone, androstenedione, and DHEA-S is a distinguishing feature. Low androgen levels correlate directly with lower anti-Müllerian hormone (AMH) and decreased antral follicle counts (AFC).
• Supplementation Outcomes: Research into androgen priming suggests clinical benefits for poor responders. Meta-analyses have indicated that DHEA and testosterone supplementation can improve oocyte yield and, in some populations, clinical pregnancy rates, although results can vary based on the specific patient subgroup and diagnostic criteria used (e.g., the Bologna criteria).

Mechanistic explanations

Androgens act as fundamental "priming" agents that prepare follicles for the later stages of development.

• Follicular Recruitment: Androgens interact with the androgen receptor (AR) on granulosa cells of preantral follicles to promote the transition from the primordial to the primary stage. This process involves the PI3K/Akt pathway and the upregulation of insulin-like growth factor-1 (IGF-1), which facilitates the recruitment of follicles into the growing pool.
• FSH Sensitization: A critical function of androgens is increasing granulosa cell sensitivity to follicle-stimulating hormone (FSH). Androgens upregulate FSH receptor (FSHR) expression via the miRNA-126* axis and by stimulating the LRH-1 promoter. This increase in receptors leads to higher FSH-induced cAMP production, effectively lowering the threshold of FSH required for a follicle to continue its maturation.

Practical considerations

While androgens are essential for healthy follicular initiation, their effects are characterized by a biphasic response. Physiological levels support growth, but excessive levels—often seen in conditions like PCOS—can lead to follicular arrest and atresia. For patients experiencing diminished ovarian reserve, the deficit in these precursors can lead to a "blunted" response to gonadotropins during fertility treatments.

Bottom line

Ovarian androgens are essential for early follicle development and for sensitizing granulosa cells to FSH. Low androgen availability is a clinically recognized contributor to poor ovarian response and diminished ovarian reserve signaling, effectively limiting the pool of follicles available for recruitment and maturation.