Personalised therapies for babies in the womb could soon become a reality, thanks to a breakthrough in medical research. For the first time, scientists have grown mini organs (known as organoids) from unborn children – essentially replicating the foetus' organs so that they can monitor their health.
Organoids are complex, 3D models of organs created from human cells. They resemble human tissue and retain the DNA of the original cells. In this case, cells from amniotic fluid: the protective liquid layer that surrounds a baby in the womb.
Currently, if doctors want to diagnose any conditions an unborn baby may have, the standard practice is to use MRI or ultrasound. But these imaging techniques provide very little information about the organs that may have malformed.
The new technique, developed by researchers at UCL and Great Ormond Street Hospital (GOSH), is the first time scientists have been able to make a functional assessment of a baby’s congenital condition before birth.
The really “innovative” part, the scientists told BBC Science Focus and other publishers, is that the method doesn’t even involve accessing the fetal tissue. Until now, scientists have only made organoids from adults or from terminated pregnancies. In these cases, they usually take a tissue sample from a biopsy or discarded piece of tissue. That’s where the amniotic fluid came in.
The study’s first author Dr Mattia Gerli said: “For me, the most exciting bit is the fact that organoids are entering more and more [into] the pharmaceutical industry, the clinic, and so on. But most of these focus on the adult.
“For the first time, we now have the possibility of bringing the technological developments… back into fetal development. Because for the first time we can access the fetus without touching the fetus, which is quite exciting on my end.”
The study was published in Nature Medicine.
The process of growing mini organs
So how did they do it? The scientists extracted live cells from the amniotic fluid of 12 pregnancies. They then used RNA sequencing to establish which organs these cells came from.
The cells are tissue-specific stem cells, meaning they are committed to forming a specific tissue during fetal development. In this case, the scientists identified cells from the lung, intestine and kidney.
The team put the cells into a culture and then watched as they began to proliferate and organise into organoids. Within two weeks, the cells had formed mini organs that exhibited many of the same functions as the organs they represented, including gene expression.
The researchers tested the organoids by comparing those from babies with a condition known as congenital diaphragmatic hernia (CDH) with healthy babies. They were able to see that those who had received treatment for the condition had organoids much closer to a healthy baby’s, showing that treatment can be monitored – and be successful – at the cellular level.
The discovery could help doctors provide more information to parents at the early stages of pregnancy. It also gives researchers access to fetal material in an understudied stage of human pregnancies (often known as ‘the black box’ of human growth).
That’s because in the UK testing can only take place within 22 post-conception weeks (the legal limit for the termination of a pregnancy). In countries like the US, fetal sampling is not legal at all.
This study got around these restrictions by using a method that doesn’t involve the fetus at all. For scientists, this breakthrough could herald a new era in fetal research – expanding what we know about human growth after 22 weeks.
“The [organoids] will allow us to study what is happening during development in both health and disease, which is something that hadn’t been possible before,” Gerli said in a press release.
“We know so little about late human pregnancy, so it’s incredibly exciting to open up new areas of prenatal medicine.”
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