Human placenta organoids grown outside womb

Scientists have produced elaborate placenta-like organoids in a dish, which may aid in the research of pregnancy disorders. 

The results, published in the journal Nature, reveal that these organoids, created from cells derived from placental tissue, are able to produce placental-specific hormones and proteins. The hormones produced by these organoids have even been shown to test positive in over-the-counter pregnancy tests.

'These placental organoids will allow us to shed light on early stages of development of the placenta but also it might be possible to develop their use for screening the safety of drugs to be used in early pregnancy,' said Magdalena Zernicka-Goetz, professor of mammalian development and stem cell biology at the University of Cambridge. 

Earlier this year Professor Zernicka-Goetz's group also managed to produce embryo-like structures from stem cells (see BioNews 935). 'By combining these two models – of the placenta and of the embryo – it should be possible to provide knowledge of how to rescue failing pregnancies,' Professor Zernicka-Goetz said.

The newly developed organoids are able to survive for extended periods and organise themselves into life-like placental structures. They are thought to most closely mimic first-trimester placentas.

Using these new mini-placentas, scientists may be able to understand in greater detail how placentas form and develop. In addition, researchers will have the ability to genetically alter them to gain insights into genetic disorders of fetal development. Researchers could also be use them to test the effect of certain drugs on placental health. 

Professor Graham Burton, a physiologist at the University of Cambridge and study co-author, said that 'these 'mini-placentas' would play an important role in helping to investigate events in early pregnancy that have profound consequences for the life-long health of the mother and her child. 

'The placenta supplies all the oxygen and nutrients essential for growth of the fetus, and if it fails to develop properly the pregnancy can sadly end with a low birthweight baby or even a stillbirth,' said Professor Burton.

Dr Vivian Li of the Francis Crick Institute in London, who was not involved in the research, said: 'The ability to culture these mini-placentas in the dish has opened up the possibilities for more complex studies such as early embryo/placental development and the response of placenta to environmental factors such as nutrients and hormonal changes in the womb.'