In the past, organoids could only be created from adult stem cells or tissues collected after an abortion. An abortion is a medical operation to end a pregnancy. The current method does not violate rules that govern direct removal of stem cells from fetal tissue. The amniotic fluid method permits scientists to get cells from fetuses during the latter parts of pregnancy. Governments around the world have different regulations covering abortions. In Britain, the legal limit for ending a pregnancy is generally 22 weeks after conception. This rule prevents British researchers from studying some parts of normal human development or diseases that are present past 22 weeks. In the United States, abortion restrictions differ by state. Most states ban the use of fetal tissue for research, said Alta Charo. She is a retired professor of law and bioethics at the University of Wisconsin at Madison. Charo was not part of the latest study.

Fetal tissue is defined by the National Institutes of Health as material coming from a dead human embryo or fetus. The tissue could come from a fetus that was aborted or did not survive because of medical problems with the pregnancy. The use of tissue from an abortion has long been controversial. Charo said the new method does not raise the same ethical concerns. And taking amniotic fluid during a womans pregnancy does not appear to add any physical risks to either fetus or pregnant woman, Charo said in an email to the AP. As part of the experiments, the researchers worked with scientists in Belgium to study the development of babies with a condition called congenital diaphragmatic hernia. This can result in organs such as the liver and intestines getting displaced into the chest. About 30 percent of fetuses with this disease die because the lungs cannot fully develop. If doctors could identify the condition before birth, they could operate on a fetus to fix it.

This microscope image provided by researchers in March 2024 shows a kidney organoid resembling renal tubules, created from cells collected from amniotic fluid. (Giuseppe Cal, Paolo De Coppi, Mattia Gerli via AP) In the experiments, researchers grew lung organoids from the cells of fetuses with the hernia condition before and after treatment. When comparing those organoids to organoids from healthy fetuses, the team was able to use the lab method to identify the affected childs condition before birth. The scientists said this ability to study working, pre-birth mini-organs is the first step toward establishing more detailed prognosis information and improving treatment methods.