Scientists in Israel have grown early-stage human eggs outside of the body for the first time.

The breakthrough could allow women who lack eggs in their ovaries to use eggs with their own genetic imprint, rather than relying on donors.

“If we succeed in the long term, it will help women, that’s for sure,” said Eliezer Shalev, dean of the faculty of medicine at the Technion–Israel Institute of Technology. He oversaw the research, which was directed by Technion student Ayelet Evron for her doctoral dissertation and conducted at the Technion and the Emek Medical Centre in Afula.

Dr Shalev and fellow researchers grew what he calls a “primordial” egg, one that is “at the same stage as in a girl before puberty”, using the fetal amnion membrane.

They set about doing this after finding that the membrane cells display signs of the same biological processes as the germ cells that develop into human eggs.

Before their research, the capability of amnion membrane cells to differentiate into germ cells with characteristics of human eggs had never been documented.

The membrane constitutes a part of the inner layer of the amniotic sac, which protects the foetus throughout the pregnancy period and is usually discarded after birth, along with the placenta.

Dr Shalev commented: “For me, the real obstacle is to reduce the number of chromosomes from 46 to 23 — at that stage it will be a real ovum.” This achievement will have important benefits for research, he said, allowing scientists to “study the physiological development of the egg” in a way that has never been possible until now, due to ethical concerns related to using eggs from a women’s ovaries.

As for the practical use of the breakthrough, Dr Shalev has high hopes that eggs that are grown from the foetal amnion membrane will be fertilised by human sperm within two to 15 years.