Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Technique may allow cancer patients to freeze eggs, preserving fertility before starting treatment


U-M researchers identify method that produces viable eggs when thawed

A new technique might allow women diagnosed with cancer the opportunity to have children when chemotherapy and radiation treatments rob them of their fertility, researchers at the University of Michigan Comprehensive Cancer Center have found. By having her eggs frozen before she begins cancer treatments, a woman can preserve the hope of one day having a baby.

Freezing eggs is one thing; thawing them safely so they can lead to pregnancy is the challenge. In the past, efforts to freeze a woman’s eggs, or oocytes, have not worked well because the cells are large. When the egg is thawed, ice crystals cause damage that prevents the egg from being fertilized.

U-M researchers looked beyond traditional techniques to a method of freezing cells called vitrification. This cryopreservation technique allows the eggs to be cooled fast enough that the transformation from liquid to solid is instantaneous. No ice crystals form and the consistency resembles a viscous glassy state. Research so far has used mouse oocytes but U-M expects to make the technology available in the clinic soon.

"With traditional slow-freeze techniques, just over half the eggs survive the thawing process. Using vitrification, we are getting 98 percent survival. For a woman with cancer, these are the only eggs she’s ever going to have, so it’s important that as many as possible remain viable," says Gary D. Smith, Ph.D., associate professor of obstetrics and gynecology, urology, and molecular and integrative physiology at the U-M Medical School, and director of the Fertility Counseling and Gamete Cryopreservation Program at the U-M Comprehensive Cancer Center.

Smith will present results of his research on Sunday, May 29, at the World Congress on In Vitro Fertilization, Assisted Reproduction and Genetics in Istanbul, Turkey.

Cancer treatments such as chemotherapy and radiation therapy can cause damage to a woman’s reproductive system and leave her unable to have children afterward. Some women may regain their reproductive function after their treatment ends and may be able to conceive on their own, while others will become infertile. Egg cryopreservation could be insurance for those women at highest risk of fertility problems after cancer treatment.

When a woman wishes to become pregnant, the vitrified eggs would be warmed and then fertilized with male sperm. The fertilized eggs would then be transferred to the uterus in the same procedure that’s used successfully when couples freeze embryos.

When eggs are warmed after vitrification, fertilization rates with conventional IVF are low. Instead, researchers have found, a single sperm cell must be injected into a single oocyte, a technique called intracytoplasmic sperm injection, or ICSI. While ICSI is an established technique used in assisted reproduction, it is more complex and costs more than traditional methods.

Using mouse oocytes, 80 percent of eggs that had been vitrified became fertilized with ICSI, with a live birth rate of about 30 percent, comparable to conventional IVF when eggs are not frozen. The fertilization and birth rates for vitrified eggs are similar to the rates for control eggs that were not vitrified.

For egg freezing to work, it must be a mature oocyte, which means a woman must have 14 days of hormone treatments to stimulate mature egg production. This could limit its applications for some women. Researchers question if it is appropriate for women with cancers fueled by estrogen, such as breast cancer. In addition, the hormone treatments require delaying the start of cancer therapy, which may not be an option for every patient.

Guidelines for patients and physicians still need to be established as the technique begins to be offered in a clinic setting, Smith says. "This is a very new technology and it requires education both of patients and physicians," Smith says.

U-M has cryopreserved eggs for one patient; however, the service is currently not offered while researchers seek approval for a clinical trial. A specialized clinic in the U-M Comprehensive Cancer Center provides counseling and information for women considering their fertility options, and the clinic currently freezes embryos for cancer patients who have a partner. The clinic also offers counseling and sperm freezing for male cancer patients. U-M will offer egg vitrification only to women facing cancer treatments, because the long-term safety of this technique remains unknown.

"In a woman with cancer, if she is going to lose her reproductive capacity because of cancer treatments, this is her only choice to have baby with her own eggs," Smith says. A clinical trial through the U-M Comprehensive Cancer Center is planned to begin by fall.

Nicole Fawcett | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>