Objective: To determine the levels of CA-125 throughout pregnancy and the puerperium to establish a baseline, thereby indicating what values may be indicative of the pathologic conditions usually associated with elevated CA-125 levels.
Study design: A prospective, longitudinal study was carried out on a consecutive series of pregnant women to determine their CA-125 levels throughout pregnancy and during the puerperium. Blood was drawn at four- to six-week intervals for clinically indicated tests. The residual sera were kept frozen, and subsequently CA-125 measurements were determined by radioimmunoassay.
Results: Of 34 women enrolled in the study, 20 completed the evaluations throughout pregnancy and in the puerperium. The remaining 14 had evaluations for varying portions of their pregnancies but not throughout pregnancy or during the puerperium. The results in these two groups were compared and found not to be statistically significantly different. For the group as a whole, the levels of CA-125 were high, with wide fluctuations in the first trimester; the levels in the early first trimester (five to eight weeks) were particularly high, with a mean of 55.8 and median of 36.2 (range, 6.9-251.2) U/mL. The levels then dropped and remained < 35 U/mL through the rest of pregnancy (including immediately prior to delivery). Another peak, with wide fluctuations, occurred soon after delivery, with a mean of 39.8 and median of 41.9 (range, 10.7-296.7) U/mL. In the late postpartum period (2-10 weeks after delivery) there was a return to baseline levels in all subjects.
Conclusion: This study showed that there is a distinct pattern in CA-125 levels during pregnancy and the puerperium. Due to the wide fluctuations in CA-125 levels in very early pregnancy and the immediate postpartum period, CA-125 values during these periods are not useful for clinical correlation with the pathologic conditions known to be associated with elevated levels of CA-125. However, further study is needed to determine whether extreme values in the first trimester or elevated levels after the first trimester are diagnostic or predictive of any conditions related to pregnancy.