Luteal Phase Testing
Why is the endometrium so important?
The lining of the uterus (endometrium) thickens, and its blood supply increases, in order to accept and support a developing embryo. This development is primarily stimulated by the reproductive hormones estrogen and progesterone.
What is the luteal phase?
The luteal phase is defined as the half of the menstrual cycle after ovulation but before menses.
Do I need an endometrial biopsy?
Some physicians choose to perform the endometrial biopsy to assess the development of the endometrium. In this test, a small sample of the endometrium is taken and examined under the microscope in the second half of the menstrual cycle. Endometrial development should correlate with the cycle day and thus the endometrium should be thickened and vascular. In most recent scientific studies, the usefulness of the endometrial biopsy has been challenged, and its routine use in the infertility evaluation has fallen out of favor.
How do I know if my luteal phase is normal?
For some patients, we choose to measure mid-luteal phase levels of progesterone rather than performing the endometrial biopsy. Seven to eight days after ovulation, progesterone levels should be elevated. We can also assess the thickness of the endometrium via ultrasound measurements.