Pfister A, et al. - Considering that a decline in ovarian reserve may decrease in corpus luteum function, researchers investigated if biomarkers of ovarian reserve are associated with luteal phase deficiency (LPD). Data from a prospective time-to-conceive cohort was secondarily analyzed. They enrolled women, 30-44 years old, without known infertility, trying to conceive for ≤ 3 months, and followed them until pregnancy. Women were assessed for biomarkers of ovarian reserve (AMH, FSH, estradiol, and inhibin B) and for LPD, defined as either luteal bleeding (≥ 1 day of luteal bleeding) or a short luteal phase (≤ 11 days, including the day of ovulation). Outcomes revealed no association of diminished ovarian reserve (DOR) with LPD, however, women of older reproductive age may display luteal phase defects due to hormone dysfunction in the early follicular phase.