Objective: Previous reports have suggested that serum CA 125 levels in patients who spontaneously abort in the first trimester of pregnancy differ from the levels of patients who successfully complete their pregnancies. Low CA 125 levels have been suggested to predict spontaneous abortion, although an increased rate of first-trimester spontaneous abortion has also been reported in women with elevated CA 125 levels early in pregnancy. The purpose of this study was to prospectively compare serum CA 125 levels of women who abort in the first trimester with levels of those women whose pregnancies progress beyond 12 gestational weeks.
Study design: A total of 188 pregnant patients had weekly serum CA 125 levels obtained after a prepregnancy baseline value was determined. Levels of the antigen in women who ultimately had a first-trimester spontaneous abortion were compared with CA 125 levels from women whose pregnancies continued past the first trimester.
Results: There was no statistically significant difference in the CA 125 levels of patients who aborted compared with those of women whose pregnancies continued. In addition, among patients with CA 125 values > 150 U/ml there was also no statistically significant difference in the proportion of patients who aborted compared with controls.
Conclusion: Serum CA 125 levels are not predictive of spontaneous abortion in the first trimester of pregnancy.