Association between diminished ovarian reserve and luteal phase deficiency.

To determine the association between biomarkers of ovarian reserve and luteal phase deficiency (LPD).Secondary analysis of a prospective time-to-conceive cohort study.Not applicable.Women attempting conception, aged 30-44 years, without known infertility.Measurement of early follicular phase serum levels of antimüllerian hormone, FSH, inhibin B, and E₂.The primary outcome was LPD, defined by luteal bleeding (LB) (≥1 day of LB) or a short luteal phase length (≤11 days).Overall, 755 women provided information on 2,171 menstrual cycles and serum for measurement of at least one biomarker of ovarian reserve. There were 2,096 cycles from 754 women in the LB cohort, of which 40% experienced LB. After adjusting for age, race, previous miscarriages, and previous pregnancies, diminished ovarian reserve (DOR) was not significantly associated with LB. Low early follicular phase FSH levels increased the odds of LB (odds ratio [OR] 1.84; 95% confidence interval [CI] 1.25-2.71), as did high early follicular phase E₂ levels (OR 1.59; 95% CI 1.26-2.01). A total of 608 cycles from 286 women were included in the analysis of luteal phase length, of which 13% had a short luteal phase. After adjusting for age, there was no significant association between DOR and a short luteal phase. The risk of a short luteal phase decreased with increasing inhibin B (OR 0.61; 95% CI 0.45-0.81).Although DOR is not associated with LPD, hormone dysfunction in the early follicular phase may contribute to LPD in women of older reproductive age.