Effect of menstruation on serum CA125 levels.

CA125 levels were measured in the sera of 54 women with normal menstrual cycle and without infectious, benign and malignant gynecologic disorders. In 54 subjects studied, 13 (24%) had no significant variations in serum CA125 levels throughout the menstrual cycle. In contrast, there 41 (76%) had significant variations in serum CA125 with peak levels (51.8 +/- 6.5 U/ml, mean +/- SEM) during menstruation. The concentration reached a normal value (17.7 +/- 1.6 U/ml, mean +/- SEM) at proliferative phase, and remained low throughout the rest phases of the cycle. The mean peak level was significantly higher than that at proliferative phase (P < 0.001), where as no significant difference in mean concentration was detected between sequential phases from proliferative phase to premenstrual phase (P > 0.1). Among 41 with variable CA125 levels in the menstrual cycle, more than half of them, namely 39% of the total (21/54), had the levels of the upper limit or normal values.