Researchers have found a new biomarker that can help in diagnosing ectopic pregnancies at an earlier stage.

About two per cent of all pregnancies in the world are known to be ectopic, which means they are implanted outside the uterus, inside a fallopian tube. In fact it is one of the main causes of pregnancy related deaths across the globe.

Up to 2% of all pregnancies in the developed world are ectopic, meaning they are implanted outside the uterus, typically inside a fallopian tube. More common in undeveloped areas, ectopic pregnancy, with severe pain in the pelvic area, acute hypovolemic shock, and the need for blood transfusion and surgical removal is the leading cause of pregnancy-related death in the first trimester worldwide.

"Current diagnosis of tubal ectopic pregnancy involves a combination of transvaginal ultrasound and measurement of serum human chorionic gonadotrophin... concentrations," write Andrew Horne, PhD, from the Centre for Reproductive Biology, Queen's Medical Research Institute, University of Edinburgh, United Kingdom, and colleagues. "However accurate and early ascertainment remains problematic and there are often delays in making the diagnosis and instigating treatment."

Researchers undertook a study based on samples of trophoblasts from 40 pregnant women, between ages 18 and 45. They noticed that each of them was undergoing a surgery for a different reason.They noted that these cells particularly differ among pregnancies; here are the key findings.

PIGF protein expression was found largely in cytotrophoblast cells, PIGF mRNA was less in trophoblast cells, and Serum PIGF levels were not detected in some tubal ectopic cases.

"We show that the angiogenic factor PIGF is reduced in trophoblast cells from tubal ectopic pregnancies when compared to that of intrauterine pregnancies. In addition, we show that this difference can be assessed systemically and that serum PIGF levels are reduced in tubal ectopic pregnancy and miscarriage," the authors write.

"This highlights that the differential secretion of angiogenic molecules associated with embryo implantation could be used to define a diagnostic biomarker strategy."

However they couldn’t collect enough trophoblast to analyze the link between serum concentrations and protein levels in the tissue. Authors noted "We believe that further diagnostic biomarkers of ectopic pregnancy could be identified by understanding the pathological angiogenesis seen in response to tubal implantation."