The Comparison of CA125 Levels in the Normal Pregnancy and Threatened Abortion

In pregnancy, the serum level of cancer antigen-125 (CA-125) increases in the first trimester and abortion. However, different studies reported conflicting results about the use of serum CA-125 to determine the prognosis of threatened abortion. In the present study, we try to determine if the measurement of CA-125 level could be used as a predictor of outcome in women with threatened abortion.

This prospective case-control study was performed on 58 patients with threatened abortion and 58 healthy pregnant women with a gestational age of fewer than 20 weeks (as the control group). In both groups, serum CA-125 level was measured. The patients were followed to determine who completed the pregnancy period and who eventually miscarried. Finally, the levels of CA-125 in these groups were compared.

The mean age of patients was 28.47 and 27.84 in the case and control groups, respectively; there was no significant statistical difference between the two groups (95% CI: -1.94 to 3.18, P=0.632). Also, there was no significant difference between them for BMI (95% CI: -1.09 to 1.38, P=0.813), gestational age (95% CI: -1.31 to 1.04, P=0.816), and parity (P=0.51). The mean serum level of CA-125 in the control group was 22.51 ± 6.82 IU/mL, and in the threatened abortion group was 27.70 ± 7.50 IU/mL. This difference was statistically significant (P<0.001). Of the patients, 51.72% with threatened abortion continued their pregnancy, and 48.28% eventually miscarried. The mean serum levels of CA-125 were 25.30±6.63 IU/mL and 30.28±7.63 IU/ml in patients who continued the pregnancy and miscarried, respectively (P=0.01).

A single measurement of the maternal CA-125 may be used as an available, inexpensive prognostic test to determine the outcome of threatened abortion. However, a small number of patients is the main limitation of the present study. More studies with a larger sample size are required to accept the role of maternal CA-125 in predicting the outcome of threatened miscarriage.