Luteal Phase Defect

Content reviewed by RESOLVE Physicians Council Member, John Storment, MD, FertilityAnswers.

The menstrual cycle can be divided into the follicular phase (the first half of the cycle, when egg development is occurring), the ovulatory phase (when the egg is released) and the luteal phase (when progesterone is produced, and embryo implantation can occur). The luteal phase defect (LPD) describes a disruption in this phase due to either inadequate progesterone production or inadequate endometrial response to progesterone. It is associated with compromised endometrial receptivity, hampered embryo implantation, and a possible increased risk of early pregnancy loss.

Historically, providers tested for LPD in various ways (luteal progesterone levels, single or multiple; timed endometrial biopsies, basal body temperature charting). However, most clinicians now focus on the follicular phase dysfunction and try to improve the ovulatory process. It is also common to give an HCG trigger injection when the follicle is a certain size to enhance ovulation and then luteal progesterone (either vaginally or intramuscular injections) to support the endometrium for a more ideal implantation. Many clinicians discourage the use of oral or topical progesterone because the amount of actual progesterone that reaches the endometrium is too low.