Serial changes of serum CA125 levels during menstrual cycles

Serial changes of serum CA125 levels during 32 menstrual cycles were examined in 32 healthy young women (19-21 years of age) charting basal body temperature (BBT) and measuring serum estradiol and progesterone levels. Analysis of BBT charts and serum progesterone levels revealed that the 32 menstrual cycles could be classified into either an ovulatory cycle with a sustained BBT temperature increase for at least 10 days (type I: 9 cycles), an ovulatory cycle with a sustained BBT temperature increase for less than 10 days (type II: 17 cycles), or anovulation (type III: 6 cycles). All 32 cycles exhibited basal CA125 levels of less than 35 u/ml throughout the cycle, except during the period of menstruation. At menstruation, 7 of the 9 cycles of type I showed a marked, transient elevation of CA125 levels from previous basal levels (a mean net increase). On the other hand, 12 of 17 cycles of type II showed only a slight elevation of CA125 levels during the period of menstruation. None of the 6 cycles of type III showed any apparent increase in CA125 levels during the period of menstruation. The mean net increase of CA125 levels during the period of menstruation in the cycles of type I was significantly higher than that of the cycles of type II (p less than 0.05) and type III (p less than 0.05). These results imply that a transient elevation of serum CA125 levels during the period of menstruation occurs in cycles with ovulation, and the levels of elevation seem to be closely associated with the duration of the sustained BBT temperature increase.