Lab Cultivated Human Eggs Give Fresh Impetus To Infertility Treatments

Highlights:

• Human eggs have been successfully grown from earliest developmental stage to full maturity in the lab recently
• Immature eggs recovered from human ovary can be matured in the lab in artificial culture medium
• Women with infertility due to cancer treatments can have their eggs recovered and grown in lab for fertilization at a later date

Human eggs at an early stage of development can be grown in the lab to a stage where they can be fertilized, thus paving the way for improved infertility treatments in the future.

This study was conducted in collaboration with the Royal Infirmary Edinburgh, The Center for Human Reproduction in New York and the Royal Hospital for Sick Children in Edinburgh, with support from the Medical Research Council. The findings of the study are published in Molecular Human Reproduction.

Improvement From Existing Technology of Growing Human Eggs In The Lab

• In earlier studies, scientists had successfully grown mouse eggs to produce young mice
• Human eggs have been grown in the lab earlier, but after recovering them at a much later stage of development

The current study is the first time a human egg has been developed from its earliest stage to final maturity in the laboratory in an artificial culture medium.

The research team collaborated to develop suitable substances in which eggs could be grown - known as culture mediums that can support egg growth and development at every stage. The work culminated after involving nearly 30 years of research with ovarian tissue obtained from women undergoing routine surgery for various reasons.

Scope of the Study

Findings of the study offer enormous scope for young women who become infertile following intensive cancer treatment regimens. If approved for use in the clinical setting, immature eggs could be recovered from the ovaries of these young women, stored and matured in the lab for future use, in particular for fertilization.

Conventionally, women who have cancer could have a piece of their ovary removed before treatment, and reimplanted later but there is a possible risk of reintroducing cancer.

• The study gives a better understanding and insight into the growth and development of eggs at various phases, and this knowledge could help future research in this field as well as in regenerative medicine

Professor Evelyn Telfer, of the School of Biological Sciences, who led the research, said: "Being able to develop human eggs in the lab fully could widen the scope of available fertility treatments."

Plans for the Future

• Optimization of conditions used for egg development and see how healthy they turn out
• Testing whether these lab grown eggs can be successfully fertilized, subject to regulatory approval

In conclusion, the results of this study offer new hope and possibility of better infertility treatments for several young women keen to have a baby following cancer treatments.

How Eggs Develop Within Ovary

Even at birth, the normal female ovary (female gonad) contains about 1-2 million immature eggs. Over her lifetime there is a continuous decline in the total number of eggs each month even before menses occurs. By the time a girl enters puberty, only about 25% of her total egg pool is left, approximately 300,000.

After puberty every month under hormonal stimulation several hundred immature eggs begin to develop, but only one dominant egg reaches full maturity and is released during ovulation for fertilization. The other eggs die. The loss of several eggs each month contributes to the decline in the number of eggs until menopause when most of the eggs become depleted.

Future fertility treatments could recover the immature eggs from the woman's ovary and mature them in the lab in artificial culture media for future use.

References:

1. Normal Ovarian Function - (https://www.mcancer.org/fertility-preservation/for-female-patients/normal-ovarian-function)

Source: Medindia