**1.2. Application area**

A circulating serum based biomarker which could accurately predict the outcome of preg‐ nancy such as ectopic pregnancy, miscarriage and viable intrauterine pregnancy. This may be used to diagnose tubal ectopic, decide the course of management (medical or surgical), and may aid in monitoring the prognosis and response to treatment in patients. This advancement in clinical diagnostic may help in significantly bringing down the maternal morbidity and mortality associated with early pregnancy failure.

#### **1.3. Research course**

Due to paucity of suitable animal models of tubal ectopic pregnancy, biomarker researches have mainly been carried out in cohorts of women with tubal ectopic, miscarriages and viable intrauterine pregnancy (IUP).

#### **1.4. Method used**

Comprehensive literature search was carried out for identifying studies on women with gestational age of less than 12 weeks in which serum markers were used to predict the outcome of pregnancy. The databases used were Medline, Embase, CINAHIL and Cochrane library, using key work search ectopic pregnancy", "tubal pregnancy" alone and in combination with "diagnosis", "screening" and "biomarkers". Only the articles published in English were included and references of all selected articles were also thoroughly searched. All the studies that assessed diagnostic accuracy were included.

#### **1.5. Status**

The factors deciding the fate of first trimester pregnancy, and hence the potential biomarkers for tubal ectopic pregnancy can be systematically categorized into two groups-Markers related to implantation site & milieu and Markers related to embryo (Fig 1). Important biomarkers in both these categories are described

**Figure 1.** Candidate biomarkers for Ectopic Pregnancy
