What Is LH?

Luteinizing hormone (LH) is a gonadotropin produced by the pituitary gland that triggers ovulation in natural cycles and affects the final maturation of oocytes. In IVF, the LH surge is suppressed to prevent premature ovulation, and a controlled trigger is used instead.

Clinical significance

During IVF stimulation, GnRH agonists or antagonists are used to suppress the natural LH surge. When follicles reach target size, an hCG trigger or GnRH agonist trigger is administered to mimic the LH surge and induce final oocyte maturation before egg retrieval.

Common confusion

LH and FSH are often discussed together but have distinct roles. FSH drives follicle growth; LH triggers the final step of oocyte maturation and ovulation.

Related reference

/glossary/follicle-stimulating-hormone →/glossary/hcg-trigger →/glossary/ovarian-stimulation →/glossary/egg-retrieval →← Back to Glossary Index

Used in

FSH →hCG Trigger →Ovarian Stimulation →Egg Retrieval →

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

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