Luteal phase defect: a review of pathophysiology

Area of Science:

• Reproductive Endocrinology
• Gynecology
• Infertility Research

Background:

• Corpus luteum function is crucial for fertility, relying on granulosa and theca cells stimulated by luteinizing hormone (LH).
• Adequate LH surge duration, amplitude, and residual pulses are vital for maintaining the 14-day luteal span.
• Granulosa cell competence involves estrogen production, progesterone synthesis via LH receptors, and oocyte maturation.

Purpose of the Study:

• To elucidate the mechanisms underlying corpus luteum defects and short luteal phase.
• To identify the primary causes of luteal phase dysfunction, distinguishing between granulosa cell and LH surge inadequacy.
• To review diagnostic methods and effective treatment strategies for luteal defects.

Main Methods:

• Review of diagnostic studies focusing on endometrial biopsy as an efficient diagnostic tool.
• Analysis of progesterone assays for diagnosing severe luteal defects, noting limitations of single assays.
• Examination of etiological factors, emphasizing hypothalamic-pituitary influences on LH surge.

Main Results:

• Corpus luteum defects with a normal luteal span duration are linked to inadequate granulosa cells or LH surges.
• Short luteal phase defects are associated with poor LH surges and absent or weak LH pulses.
• Endometrial biopsy is identified as the most effective diagnostic method for luteal defects.

Conclusions:

• Luteal phase defects are often multifactorial, primarily stemming from hypothalamic-pituitary factors affecting the LH surge.
• Repetitive defects require careful evaluation due to potential variations in cycle-to-cycle factors.
• Substitution progesterone therapy is considered the most effective treatment for luteal defects, despite diagnostic challenges.