Reproductive · Year 2 · from Reproductive
Case 2: Luteal Phase Defect
Clinical Image
Source: Wikipedia - Corpus luteum - CC BY-SA 3.0
Case Presentation
A 34-year-old woman presents for evaluation after two first-trimester miscarriages in the past 18 months. She and her husband have been trying to conceive for 2 years. Her menstrual cycles are regular at 24-25 days. She reports consistent premenstrual spotting for 3-4 days before the onset of her full menstrual flow. She uses ovulation predictor kits and typically gets a positive test on day 11 or 12. Basal body temperature charting shows a biphasic pattern with the luteal phase lasting only 9-10 days before temperature drops and menses begins. Physical examination is unremarkable. Day 21 (mid-luteal) progesterone level is 6.2 ng/mL (low-normal). Given her short luteal phase, low mid-luteal progesterone, and premenstrual spotting, a diagnosis of luteal phase defect is considered. She undergoes hysterosalpingogram which shows normal tubal patency. Her husband's semen analysis is normal. The patient conceives on a subsequent cycle but given her history, progesterone supplementation (vaginal progesterone 200 mg twice daily) is initiated after positive pregnancy test and continued through 10 weeks of gestation. She carries the pregnancy to term without complications.
Key Learning Points
- The luteal phase is typically 14 days (+/- 2 days); a short luteal phase (<10 days) may indicate inadequate corpus luteum function
- Progesterone from the corpus luteum is essential for secretory transformation of the endometrium, creating an environment suitable for implantation
- Luteal phase defect may present with premenstrual spotting, short luteal phase, and recurrent early pregnancy loss
- Progesterone supplementation is commonly used in early pregnancy for women with history of recurrent loss, though evidence for efficacy outside of IVF is debated