Scientists have grown "mini placentas" in a breakthrough that could transform research into the underlying causes of miscarriage, still in pregnancy and other disorders.
The tiny organoids mimic the placenta in the early stages of the first trimester and will be used to understand how tissue develops in pregnancies, and what goes wrong when it fails.
The mini placentas are so much like the real thing they can fool over-the-counter pregnancy tests. "If we are pregnancy sticking into the medium from the organoids it reads 'pregnant'," said Ashley Moffett, a senior researcher on the team and professor of reproductive immunology at Cambridge University.
In a healthy pregnancy the placenta grows and attaches to the wall of the womb where it provides oxygen and nutrients for the baby, while removing waste from the fetus blood. It also secretes hormones into the mother.
Pregnancy can fail when the embryo does not implant properly and the placenta does not attach. Understanding what goes wrong in these cases has been hard to find because scientists do not have the placements to study, and the placements of animals are too different to make meaningful comparisons.
"We can now begin to do experiments on how placental development occurs in the uterine environment," said Moffett.
The Cambridge team grew from their laboratory using cells from frond-like structures called villi which are found in placental tissue. The cells are organized themselves into capable multi-cellular structures that are secreting the proteins and hormones that affect the metabolism of the mother during pregnancy.
The organoids range from size is from a millimeter to half a millimeter. They can be frozen and stored and then thrown out when needed.
Researchers want to use the organization to study some of the most common disorders, such as pre-eclampsia, stillbirth and growth restriction. But the lab grown mini-placent will also help understand how certain infections affect babies.
But it is not clear how the virus crosses the placenta when the very similar dengue virus does not.
Other work will investigate the hormones and proteins secreted by the organization as they grow, with a view to identifying substances that could provide early warning that the placenta is not working properly. "These women could be followed more closely," said Moffett. Details of research are published in Nature.
Margherita Turco, lead author of research, said: "The placenta is absolutely essential for supporting the baby as it grows inside the mother. When it doesn't function properly it can result in serious problems, from pre-eclampsia to miscarriage, with immediate consequences for both mother and child. "
The mini-placentas could also be used to check the safety of new drugs during early pregnancy, and shed light on how chromosome abnormalities can be upset a baby's normal development. Further on the placentas could provide stem-cell therapies for failing pregnancies, the researchers said.