Purpose of review: Although the key role of luteinizing hormone in ovarian function, the promotion of follicular growth and maturation, is widely acknowledged, its usefulness as a predictor of ovarian status, and as a supplement during fertility treatment, remains controversial.
Recent findings: Luteinizing hormone alone is not an effective predictor of ovarian function. In combination with follicle-stimulating hormone, as the so-called follicle-stimulating hormone: luteinizing hormone ratio, it serves as a useful marker of ovarian status. Although published data on luteinizing hormone supplementation during ovarian hyperstimulation are somewhat limited, recent well-designed studies suggest a beneficial effect of: (1) luteinizing hormone supplementation for women with inadequate responses to follicle-stimulating hormone-only stimulation; (2) in primarily young patients with low baseline luteinizing hormone levels and, consequently, insufficient remaining endogenous luteinizing hormone concentration during pituitary suppression; and (3) in older women with higher baseline luteinizing hormone levels and age-appropriate ovarian function, who require higher luteinizing hormone thresholds, even during pituitary suppression.
Summary: Luteinizing hormone levels, as a component of the follicle-stimulating hormone: luteinizing hormone ratio, contribute to the assessment of ovarian function, whereas the supplementation of luteinizing hormone on an individualized basis, in carefully selected patients, improves outcomes of ovarian stimulation with gonadotropins.