The world's first real-time video captures the moment of human embryo implantation

A research team from the Institute of Bioengineering of Catalonia (IBEC) and other institutions has become the first in the world to capture real-time footage of the moment a human embryo implants in the uterine lining. Capturing the entire implantation process in a moving image could lead to improved fertility treatments and increased success rates in in vitro fertilization.

Traction force and mechanosensitivity mediate species-specific implantation patterns in human and mouse embryos | Science Advances
https://www.science.org/doi/10.1126/sciadv.adr5199

Human embryo implantation recorded in real time for the first time - Institute for Bioengineering of Catalonia
https://ibecbarcelona.eu/graban-por-primera-vez-el-proceso-de-implantacion-de-un-embrion-humano

The study was conducted using a 3D system that mimics the outer layer of the uterus. Using a fibrous protein gel, which is also found in skin and tendons, the researchers developed an experimental 'artificial uterus' platform that allows embryos to implant outside the uterus. The device allows researchers to track the extent to which the embryo pushes and pulls against its surroundings using fluorescent markers and a microscope. Two versions of the device are available: one in which the embryo is placed on a flat gel (2D) and one in which the embryo is placed inside a drop of collagen (3D). Both versions mimic the early environment found in the uterus.

The actual footage can be seen below. As a result of the observations, the human embryo showed a fairly powerful movement, burrowing deep while pulling the surrounding collagen toward itself.

Human embryo loop - YouTube


The video below shows a side-by-side comparison of the implantation process in mouse and human embryos. Observations revealed that human embryos exhibit a significantly different implantation pattern than mouse embryos. While mouse embryos attach to the surface of the endometrium, human embryos penetrate completely into the uterine tissue. During this penetration process, the embryo not only releases enzymes that break down the surrounding tissue, but also exerts significant mechanical forces to remodel the surrounding matrix in preparation for implantation and penetration.

Lable free implanting embryos loop - YouTube


The following video shows a human embryo sinking into the uterus during implantation, with the top view shown above and the bottom view shown from the side. The research team points out the importance of force in this implantation process, suggesting that a successfully implanted embryo displaces the surrounding matrix appropriately, and that this mechanical interaction may determine whether implantation is successful. The results also suggest that embryos respond to external physical forces, and that uterine contractions may affect implantation.

HUMAN EMBRYOS ORTOGONAL DIGGING HOLE - YouTube


The experiment also confirmed that differentiation after implantation was progressing, with the cells that make up the outside of the embryo beginning to produce hormones that indicate pregnancy. Examination of the culture medium revealed that hormone levels were detected at an average of approximately 109.5ng/ml after two days of culture, demonstrating that the changes seen in early human pregnancy could be reproduced in an experimental environment.

Implantation failure is one of the main causes of miscarriage, accounting for approximately 60% of all miscarriages. The uterine model developed in this study is expected to be used as a platform to test various environments and compounds that may improve implantation. The research team also stated that the results of this study may contribute to improving implantation rates in infertility treatments, selecting higher-quality embryos, and optimizing in vitro fertilization processes.