Role of Tumor Marker CA-125 in the Detection of Spontaneous Abortion

The clinical diagnosis of threatened abortion is presumed when any bloody vaginal discharge or bleeding appears during the first trimester of pregnancy. A prospective study on women with threatened abortion reported that women older than 34 years had an odds ratio of 2.3 for miscarriage (Falco et al., 1996). Some women who bleed in early pregnancy, approximately half of them, will abort (Weiss et al., 2004). Occasionally, bleeding may persist for weeks, and then it becomes essential to decide whether there is any possibility of continuation of the pregnancy or not. The diagnosis of spontaneous abortion currently depends on a combination of ultrasonography and nine hormonal methods including serum human chorionic gonadotropin (HCG), estradiol (E2), estrone, estriol, progesterone, human placental lactogen, cortisol, urine HCG and urine estrogen (Gerhavd and Runnebaum 1984; Zeimet et al., 1998; Osmanagaoglu et al., 2010). Another parameter that could be used as a predictive marker for a spontaneous abortion or subsequent outcome of pregnancy is Cancer Antigen-125 (CA-125). This antigen is a cell surface high molecular weight glycoprotein. It is a mucin like coelomic antigen, which is detected in 80% of non-mucus epithelial carcinomas of ovary. This antigen is secreted from normal tissues, such as coelomic epithelium, amnion and their derivatives including respiratory system, mesenteric organs and epithelium of female genital system (Berek 2002). An increased CA-125 level is due to genital or non-genital origins. Nongenital causes include hepatic diseases, peritonitis, renal failure, breast, colon and lung cancer, and tuberculosis. Genital causes include: pelvic inflammatory diseases, endometriosis, adenomyosis, leiomioma, ectopic pregnancy, endometrial and ovarian cancer.