China makes womb on a chip to shed light on first days of pregnancy

Chinese scientists have developed a "womb on a chip," a three-dimensional microfluidic model that replicates the human uterine lining (endometrium) to study embryo implantation, a critical and previously hard-to-study stage of early pregnancy. This chip-based system uses human endometrial cells embedded in gel-like layers to form tissue that closely mimics the natural uterine environment. The model supports the full implantation process, including embryo attachment and invasion, by introducing either real human blastocysts or lab-made blastoids derived from stem cells. This advancement overcomes ethical and practical limitations of studying early human pregnancy and offers a more accurate and detailed platform than previous two-dimensional cultures. The researchers demonstrated that embryos implanted successfully within the chip, recapitulating key stages such as apposition, attachment, and invasion, as well as early post-implantation development. Importantly, when using cells from women with recurrent implantation failure (repeated IVF failures), the embryos showed significantly reduced implantation success, reflecting