Luteal blood flow and luteal function

Abstract

Background: Blood flow in the corpus luteum (CL) is associated with luteal function. The present study was undertaken to investigate whether luteal function can be improved by increasing CL blood flow in women with luteal phase defect (LFD).

Methods: Blood flow impedance in the CL was measured by transvaginal color-pulsed-Doppler-ultrasonography and was expressed as a resistance index (RI). The patients with both LFD [serum progesterone (P) concentrations < 10 ng/ml during mid-luteal phase] and high CL-RI (>/= 0.51) were given vitamin-E (600 mg/day, n = 18), L-arginine (6 g/day, n = 14) as a potential nitric oxide donor, melatonin (3 mg/day, n = 13) as an antioxidant, or HCG (2,000 IU/day, n = 10) during the subsequent menstrual cycle.

Results: In the control group (n = 11), who received no medication to increase CL blood flow, only one patient (9%) improved in CL-RI and 2 patients (18%) improved in serum P. Vitamin-E improved CL-RI in 15 patients (83%) and improved serum P in 12 patients (67%). L-arginine improved CL-RI in all the patients (100%) and improved serum P in 10 patients (71%). HCG improved CL-RI in all the patients (100%) and improved serum P in 9 patients (90%). Melatonin had no significant effect.

Conclusion: Vitamin-E or L-arginine treatment improved luteal function by decreasing CL blood flow impedance. CL blood flow is a critical factor for luteal function.

Figure 1

Correlation between blood flow impedance of the corpus luteum and serum progesterone concentrations. (a): Correlation between corpus luteum-resistance index (CL-RI) and serum progesterone concentrations (n = 46). (b): Receiver operating characteristic (ROC) curve analysis. CL-RI and serum progesterone concentrations were measured during the mid-luteal phase (6–8 days after ovulation). Serum progesterone concentrations were significantly and negatively correlated with CL-RI (p < 0.01, single regression analysis). ROC curve analysis was performed to determine the cutoff value of the CL-RI providing the best values of sensitivity and specificity for determination of normal luteal function and luteal phase defect. The cutoff value of 0.51 provided the best combination with 84.3% sensitivity and 85.6% specificity to discriminate between normal luteal function and luteal phase defect.