However, inadequate follicle development may also be causing the low progesterone levels. If follicle development is normal, then progesterone supplementation during the luteal phase is normally the correct treatment. Women whose linings fail to respond to normal progesterone levels often have normal follicle development and adequate progesterone levels at 7 days past ovulation. An ultrasound image of the lining at seven dpo, however, will show a lining that has failed to convert from the triple layer lining typical of the time of ovulation. In this case, women are often given additional progesterone supplementation in the luteal phase in the hope that a higher level will be the push that the lining needs to convert appropriately.
Some doctors use injections of human chorionic gonadotropin to further stimulate the corpus luteum.
However, these injections can cause false positive pregnancy results. Many doctors feel comfortable basing an LPD diagnosis on progesterone levels, luteal phase length, and ultrasound lining appearances. However, especially in persistent cases, many doctors will use an endometrial biopsy. The endometrial biopsy is normally performed a few days before the next menstrual cycle is expected, ideally after a negative pregnancy result for the cycle has been obtained. The procedure consists of sampling a small amount of uterine lining and sending it to a pathologist for evaluation.