Understanding early pregnancy, towards a new vision on the treatment of human infertility.

The last 20 years research on Assisted Reproductive Technologies (ART), focused almost exclusively on embryos. Despite the impressive technological advances the live birth rate has stalled at between 25% – 27%. The uterus, where the embryo must implant and develops, had been poorly studied. A successful pregnancy is the result of a complex molecular and cellular exchange established between the mother and the embryo since the early stages of pregnancy until baby deliver.

Today, we are able to transfer “good quality embryos” (based solely on morphological characteristics) into the maternal uterus, however, we don’t know if the uterus is ready to receive the embryo. Out of 50% of the ART failure cases are due to the impossibility by the maternal uterus to host the embryo at the moment of the embryo transfer. Also a “non-receptive uterus” can explain why 15% of couples using ART never become parents.

We must then work to understand both the fundamental and clinical aspects of the early pregnancy, and specially the complexity of the molecular and cellular exchanges during the embryo implantation in the maternal uterus. Understanding the EMByo Implantation Control at both embryo and maternal levels is the goal of the EMBIC network of excellence (www.embic.org). This consortium partially financed by the European Commission is composed of more than 200 researchers and clinicians from 18 leading European institutions of 9 countries. A better understanding of this early “molecular conversation” between the mother and the embryo will permit us to propose new therapies and technologies increasing ART success rates.