Question 3

A 30-year-old nulligravid woman has been trying to conceive for the past year. She is unsure when she is ovulating. She has 28 day cycles and is cycle day 21. Ovulation can be confirmed by observing an increase in:

Answer Choices:

Estradiol

Follicle stimulating hormone

Luteinizing hormone

Progesterone

Correct Answer:

Progesterone

Explanation:

  • Ovulation is most easily documented by a mid-luteal phase serum progesterone level (obtained 1 week prior to menses)

  • A day 21 progesterone > 3 ng/mL is evidence of recent ovulation

  • Progesterone is secreted by the corpus luteum only after ovulation