Diagnosis and treatment of luteal phase deficiency: a Committee Opinion.

Luteal phase deficiency (LPD) is a clinical diagnosis associated with abnormal luteal phase length of ≤10 days. Potential etiologies of LPD include inadequate progesterone duration, inadequate progesterone levels, or endometrial progesterone resistance. Luteal phase deficiency has been described in association with medical conditions, but also in fertile, normally menstruating women. Although progesterone is important for the process of implantation and early embryonic development, LPD has not been proven to be an independent entity causing infertility or recurrent pregnancy loss. Controversy exists regarding the multiple proposed measures for diagnosing LPD, and assuming it can be diagnosed accurately, whether treatment improves outcomes. This document replaces the document of the same name, last published in 2021 (Fertil Steril 2021;115(6):1416-23).