The predictive value of serum cancer antigen 125 (CA125) levels on pregnancy outcome in threatened miscarriages.

Background Spontaneous miscarriages are common pregnancy complications which result in psychological and emotional burden in the affected women. It is therefore necessary to identify biomarkers that can predict pregnancy outcome in women with threatened miscarriages so as to assist in their counselling and management. Methods The study compared levels of maternal serum CA125 in 65 pregnancies with threatened miscarriages (study group) with 65 normal intrauterine pregnancies (control group) between 6 weeks and 19 weeks + 6 days gestation using an enzyme linked immunosorbent assay (ELISA) technique. Results The mean age of the study and control groups were 29.5 ± 0.14 years and 30.1 ± 0.14 years, respectively. The mean serum CA125 in the study group was 30.1 ± 1.1 IU/mL while that of the control group was 22.9 ± 1.2 IU/mL and this was statistically significant (P = 0.0001). The mean serum CA125 level in the women whose pregnancies were aborted (aborters) was 34.8 ± 1.4 IU/mL while the mean value among those whose pregnancies continued till term (non-aborters) was 27.3 ± 1.2 IU/mL. This was statistically significant (P = 0.001). Further analysis using CA125 ≥36.2 IU/mL (mean value of serum CA125 among aborters + 1 standard deviation) as a threshold for intrauterine pregnancies that eventually got aborted showed a sensitivity of 66.7%, specificity of 83.3%, positive predictive value of 55.6%, negative predictive value of 88.9% and the diagnostic effectiveness (accuracy) was 79.4%. Conclusion The measurement of serum CA125 is a useful predictor of pregnancy outcome in threatened miscarriages.