Researchers create replica of womb lining to study early stages of pregnancy

New Delhi, Dec 26 (PTI) Researchers have created a replica of womb lining or endometrium which allowed them to study the implantation of human embryos -- process that signals start of a pregnancy.

Described in a paper in the journal Cell, the model allows scientists to study interactions between the womb and embryo, and look for causes behind implantation failure -- a main reason for early pregnancy loss, researchers from the Babraham Institute in the UK and the US' Stanford University said.

"Understanding embryo implantation and embryo development just after implantation has significant clinical relevance as these stages are particularly prone to failure," said lead researcher Peter Rugg-Gunn, senior group leader at the Babraham Institute.

"In particular, the high rate of implantation failure represents one of the main limiting factors for IVF success," Rugg-Gunn said.

The researchers said that about a week following fertilisation -- fusing of sperm and egg cell -- the developing embryo embeds into the womb lining, or the endometrium. The stage is not understood well, due to the difficulty of observing the embryo during and after implantation, they said.

The 3D model of the womb lining is built in a step-by-step process by bringing together components of the endometrial tissue and looks to replicate the complex physiological properties and cellular composition of the endometrium, the team said.

They isolated two essential cell types that form the endometrial tissue -- epithelial cells and stromal cells -- from tissue donated by healthy people who had endometrial biopsies, information from which was used to identify components that give the womb lining its structure.

The model supported a post-implantation development of the embryo, allowing for an analysis of embryo stages -- 12-14 days post-fertilisation -- that have been largely unexplored, the researchers said.

"We were really excited to see that our system released essential factors that are needed to nourish the embryo in the first few weeks of pregnancy. Previous models haven't been able to achieve this, so this represented a breakthrough for us," Rugg-Gunn said.

Analysing cells at the embryo implantation sites, the researchers were able to profile cells at the interface of embryo and endometrium model, "effectively listening in to the molecular communication between the tissues".

The results provide new insights into the complex interactions between the embryo and endometrial environment that underpin embryo development immediately after implantation, the team said.

The womb lining model also helped the researchers observe important landmarks in early development of the placenta -- an organ that develops in the uterus providing oxygen and nutrients to the foetus and removing waste. PTI KRS NB