London: Identification of a protein involved in the development of the human placenta could improve treatments for recurrent miscarriages, say researchers. The study showed that a protein called Syncytin-1, which was the result of a viral infection of our primate ancestors 25 million years ago, is first secreted on the surface of a developing embryo even before it implants in the womb. This means the protein is likely to play a major role in helping embryos stick to the womb as well as the formation of the placenta. This fundamental understanding of the earliest stages of human embryo development is crucial for improving current treatments for a variety of stressful complications during pregnancy such as recurrent miscarriages, fetal growth restriction syndrome and pre-eclampsia -- a life threatening condition of elevated maternal blood pressure during pregnancy, the study said. "Recurrent miscarriages, fetal growth restriction syndrome and pre-eclampsia are all significant and very stressful complications of pregnancy,” said lead author of the study Harry Moore from the University of Sheffield in England. "Eventually we may be able to develop blood tests based on our results to identify pregnancies that might be at risk and also develop appropriate therapies,” Moore said. The findings suggest that not all viral infections are necessarily as disastrous as the Zika virus infection that can have devastating effects on fetal development. "Amazingly the Syncytin-1 gene is the result of a viral infection of our primate ancestors 25 million years ago. The viral DNA got into our ancestors genome and was passed on through heredity and the gene involved in the fusion of the virus with cells for infection was co-opted and became Syncytin-1. Without it humans probably would not have evolved," Moore noted. The findings appeared in the journal Human Reproduction. The researchers said they will now investigate whether the level of Syncytin-1 secretion on the pre-implantation embryo is somehow related to outcome of pregnancy in women undergoing in vitro fertilisation (IVF).