From the Guidelines
The corpus luteum is a temporary endocrine structure that forms in the ovary after ovulation, characterized by a thick-walled cyst less than 3 cm with a crenulated inner margin, internal echoes, and peripheral flow, as defined by the O-RADS US risk stratification and management system 1.
Key Characteristics of Corpus Luteum
- Develops from the empty follicle that previously contained the egg cell
- Produces progesterone and some estrogen to prepare the uterine lining for potential pregnancy
- Crucial for maintaining the early stages of pregnancy, with proper function important for reproductive health
- Problems with corpus luteum function can lead to luteal phase defects, affecting fertility or early pregnancy maintenance
Diagnostic Considerations
- Ovarian EP (ectopic pregnancy) is exceedingly rare and presents diagnostic challenges, as it often mimics a corpus luteum 1
- Diagnosis of ovarian EP should not be made unless a yolk sac, embryo, or cardiac activity is definitely seen in the intraovarian lesion
- The overwhelming majority of intraovarian thick-walled cysts represent a corpus luteum, as stated in the O-RADS US risk stratification and management system 1
Clinical Implications
- Corpus luteum function is essential for reproductive health, and any issues with its function can impact fertility or early pregnancy maintenance
- Accurate diagnosis and differentiation from ovarian EP are critical to ensure proper management and treatment
- The O-RADS US risk stratification and management system provides a consensus guideline for the evaluation and management of ovarian and adnexal lesions, including the corpus luteum 1
From the Research
Definition of Ovarian Corpus Luteum
- The corpus luteum is a temporary endocrine gland that develops after ovulation from the ruptured follicle during the luteal phase 2
- It is the source of progesterone in the luteal phase of the cycle and the initial two-thirds of the first trimester of pregnancy 3
- The corpus luteum produces a huge amount of the hormone progesterone, which makes the womb ready for pregnancy 3
Function of the Corpus Luteum
- Normal luteal function is required for fertility and the maintenance of pregnancy 3
- Progesterone production from the corpus luteum is critical for natural reproduction 4
- The corpus luteum is an important contributor of steroid hormones, particularly progesterone, and is critical for the maintenance of early pregnancy 2
Problems Associated with Corpus Luteum Dysfunction
- Luteal-phase dysfunction can result in premature regression of the gland, with a subsequent shift to an infertile cycle 2
- If the corpus luteum is not working correctly, there could be problems getting pregnant or staying pregnant 3
- Luteal phase deficiency in natural cycles is a plausible cause of infertility and pregnancy loss 4