**2.** CA-125

Conflicting results have been reported by several groups regarding the status of circulating CA-125 in EP with some groups reporting an increase, some decrease and few found no difference between viable IUP and EP [117-121]. In our experience in the cohort of patients, we found CA125 concentration to be significantly higher in woman with miscarriages compared to patients with normal IUP, but not in women with ectopic compared to IUP [Unpublished paper]. Women with **IU** abortion were found to have significantly higher CA-125 levels, compared to the other two groups. Katsikis et al also reported that when using CA-125 concentration of more than 41.9 U/ml as a threshold for the diagnosis of IU abortive pregnancy, sensitivity was 80% and specificity was 87% for discriminating it from EP [122].

**3.** Antibodies to C1q complement

C1q complement has been shown to promote trophoblast invasion of deciduas, a crucial step in normal placental development. Animal models have demonstrated that the lack of C1q is characterized by poor trophoblast invasion and pregnancy failure [123,124]. Studies based on these observations have measured the levels of antibodies to C1q complement in early pregnancy failure have been conducted. Daponte et al failed to observe any difference between normal viable IUP, EP and other abnormal IUP [116]. As new studies would be undertaken by different groups, more information regarding this marker is likely to emerge.


The biomarkers studied in ectopic pregnancy with their current status are summarized in table 1.


**Table 1.** Current status of biomarkers of tubal Ectopic pregnancy
