
Human eggs have been fully grown in a laboratory, in a move that could lead to improved fertility treatments.
Scientists have grown egg cells, which were removed from ovary tissue at their earliest stage of development, to the point at which they are ready to be fertilised.
The advance could safeguard the fertility of girls with cancer ahead of potentially harmful medical treatment, such as chemotherapy. Immature eggs recovered from patients' ovarian tissue could be matured in the lab and stored for later fertilisation.
Conventionally, cancer patients can have a piece of ovary removed before treatment, but reimplanting this tissue can risk reintroducing cancer.
The study has also given insight into how human eggs develop at various stages, which could aid research into other infertility treatments and regenerative medicine.