"Miscarriage remains the most common complication of pregnancy despite many advances in the understanding of early pregnancy. Loss of three or more consecutive pregnancies before 24 weeks of gestation is the most accepted definition for recurrent miscarriage (RMC) in Europe, but has recently been defined by the American Society for Reproductive Medicine as a disease with two or more failed pregnancies. Despite best efforts to identify the underlying causes for RMC, it remains ‘unexplained’ in the majority of cases. Chromosomal errors appear to be common in the pre-implantation developing embryos6, 7, which predispose to increased risk of pregnancy losses. High rates of chromosomally abnormal cells within human embryos mean that the reproductive success is dependent on the endometrial ability to distinguish between normal and abnormal embryos. In vitro studies have provided convincing evidence that perturbation in the bio‐sensor function of the decidualised endometrium is an important mechanism underpinning RMC."