What Is FSH?

Follicle stimulating hormone (FSH) is a gonadotropin produced by the pituitary gland that stimulates the growth and maturation of ovarian follicles. In IVF, synthetic FSH is the primary medication used for ovarian stimulation.

Clinical significance

Baseline FSH levels measured on Day 2 or 3 of the menstrual cycle help assess ovarian reserve. Elevated baseline FSH (above 10 IU/L) may indicate diminished ovarian reserve. During IVF, injectable FSH medications drive multiple follicles to develop simultaneously.

Common confusion

FSH levels fluctuate cycle to cycle. A single elevated FSH reading does not definitively diagnose poor ovarian reserve. AMH and antral follicle count provide more consistent assessments.

Related reference

/glossary/ovarian-stimulation →/glossary/ovarian-reserve →/glossary/amh →/glossary/antral-follicle-count →/glossary/luteinizing-hormone →← Back to Glossary Index

Used in

Ovarian Stimulation →AMH →Antral Follicle Count →LH →Ovarian Reserve →

This content defines terminology for educational orientation. It does not constitute medical advice.

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