In an infertility evaluation, how is ovulatory status typically verified?

• A. Endometrial biopsy during the luteal phase.
• B. Serial mid-luteal serum progesterone measurements.
• C. Basal body temperature charting alone.
• D. Measuring LH surge during the follicular phase.

Answer: (B)

Verifying ovulatory status hinges on confirming luteal-phase progesterone production. After ovulation, the corpus luteum ramps up progesterone, creating a rise in serum levels during the mid-luteal phase. Measuring these levels in the mid-luteal window—and doing so across several cycles if needed—provides direct evidence that ovulation occurred and that the luteal phase is functioning properly.

Why this is the best approach: it directly reflects the hormonal consequence of ovulation—the formation and activity of the corpus luteum. A consistently elevated mid-luteal progesterone confirms ovulation and adequate luteal support, which is central to fertility.

Why other options don’t fit as well: an endometrial biopsy during the luteal phase is invasive and not routinely used to verify ovulation; it assesses endometrial histology rather than confirming ovulation itself. Basal body temperature charting can indicate a post-ovulatory temperature rise, but it is unreliable and can be affected by many factors, making it less definitive. Measuring an LH surge in the follicular phase signals that ovulation is likely but does not prove that ovulation actually occurred in that cycle, making it less conclusive than directly assessing mid-luteal progesterone.