Researchers at the Babraham Institute and Stanford University have developed a highly realistic 3D model of the human womb lining, known as the endometrium, to study how human embryos implant during the earliest stages of pregnancy.
The model is made using donated endometrial tissue and recreates key features of the womb lining, including its cell types, structure and hormone responses. Unlike previous systems, it responds to the embryo in a way similar to a real pregnancy, producing essential factors needed to nourish the embryo.
Using donated early-stage human embryos from IVF procedures, the researchers were able to observe implantation as it happened. The embryos attached to and invaded the engineered womb lining, increased production of hCG — the hormone detected in pregnancy tests — and showed signs of early post-implantation development.
The system also allowed scientists to study embryo development around 12–14 days after fertilisation, a stage that is normally very difficult to observe. They saw early signs of placental development, including cells and structures that will later help form the interface between mother and foetus for oxygen and nutrient exchange.
The researchers used single-cell analysis to examine communication between the embryo and the womb lining. This could help explain why implantation sometimes fails, which is a major factor limiting IVF success and a common cause of early pregnancy loss.
The work could also help researchers better understand infertility, miscarriage and pregnancy complications such as pre-eclampsia. In future, personalised versions of the model could potentially be used to study why some individuals have difficulty becoming pregnant, or to test treatments that improve the womb lining’s receptiveness to an embryo.
Credit: Babraham Institute