For a couple trying to conceive for 15 months, what would be the most appropriate next step for the female partner?

In cases where a couple has been trying to conceive for 15 months without success, a thorough assessment of both partners' reproductive health is essential. Testing for luteal-phase progesterone levels is relevant because it can help determine whether the woman is ovulating and if her luteal phase is functioning adequately. The luteal phase is the time between ovulation and the start of menstruation, and adequate progesterone levels during this phase are crucial for creating an environment suitable for embryo implantation.

Measuring progesterone levels is a relatively straightforward and non-invasive step that can provide significant insight into the woman's hormonal health. If ovulation is confirmed and the luteal phase is adequate, other underlying issues can be explored, leading to a more targeted reproductive health strategy.

If the luteal-phase progesterone level is low, it denotes a potential issue that could hinder implantation and pregnancy, informing subsequent steps in the fertility evaluation pathway. This makes it a logical next step in a comprehensive evaluation process after 15 months of attempting conception.