Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First baby is born after oocytes were matured in the lab and frozen

04.07.2007
3 more women are pregnant by the same method

The first baby to be created from an egg that had been matured in the laboratory, frozen, thawed and then fertilised, has been born in Canada. Three other women are pregnant by the same process. The research was presented to the 23rd annual meeting of the European Society of Human Reproduction and Embryology today (Monday 2 July).

The baby girl was born to one of 20 patients with polycystic ovarian syndrome (PCOS) or with ovaries that had been detected to be polycystic by ultrasound (U/S), who took part in the trial at McGill Reproductive Center, Montreal, Canada. The baby is progressing well.

Dr Hananel Holzer, who led the team, is an assistant professor at the Center and coordinates the fertility preservation programme there [1]. He said: “Freezing a woman’s eggs (or oocytes) has become an important and integral part of fertility treatment, and the introduction of new freezing techniques such as oocyte vitrification has increased significantly both oocyte survival and resulting pregnancy rates. However, to date, the pregnancies reported have been the result of fertilisation of frozen or vitrified and then thawed oocytes that had been collected after ovarian stimulation. Unfortunately, some patients seeking fertility preservation may not have enough time to undergo ovarian simulation, or may suffer from a medical condition deemed by some oncologists as a relative contraindication to hormonal stimulation, such as oestrogen-receptor-positive breast cancer.

“In these circumstances, oocytes can be collected from the ovaries without hormonal stimulation, and the immature oocytes can be matured in the laboratory before being frozen or vitrified. But, until now, it was not known whether oocytes collected from unstimulated ovaries, matured in vitro and then vitrified, could survive thawing, be fertilised successfully and result in a viable pregnancy after embryo transfer.

“We have demonstrated for the first time that it is possible to do this and, so far, we have achieved four successful pregnancies, one of which has resulted in a live birth. The other three pregnancies are ongoing. These results are preliminary and the pregnancy rate is probably associated with a learning curve; indeed three of the pregnancies were achieved in the last five patients.”

Dr Holzer warned that the research was still in its early stages and that it had not yet been proven in cancer patients. “It has the potential to become one of the main options for fertility preservation, especially for patients who cannot have ovarian stimulation and all patients who do not have enough time to undergo ovarian stimulation,” he said. “However, we have to remember that these are only preliminary results from a small number of patients who were not cancer patients themselves. As for all methods for fertility preservation, they should be looked at as preliminary and experimental. We need to inform the patients about the early stage of these treatments without giving any false hopes.”

Women who have been diagnosed with cancer face the prospect that the treatment they receive for their disease might make them infertile by destroying their ovarian reserve of oocytes. At present, there is the still experimental option of having the ovarian tissue removed, frozen and then transplanted back at a later date; however, there is the theoretical risk that this could re-introduce metastatic cancer into the woman. For women who are infertile due to PCOS, the administration of hormones to stimulate their ovaries to produce eggs can have the dangerous side-effect of over-stimulating their ovaries, resulting in the potentially life-threatening ovarian hyperstimulation syndrome (OHSS). Therefore, being able to obtain successful pregnancies after retrieving immature eggs from unstimulated ovaries is an important step forward for women in these situations.

The researchers selected 20 patients, with an average age of about 30, who were infertile, had polycystic ovaries and had agreed to have their eggs frozen as part of their in vitro maturation (IVM) treatment. A total of 296 oocytes were collected from the patients, of which 290 were immature. The oocytes were matured in the laboratory for 24-48 hours and then 215 were frozen using the Cryoleaf oocyte vitrification kit developed at McGill. They remained frozen for no longer than a few months, and then were thawed. From these, 148 oocytes survived the thawing process and were fertilised via ICSI (intra-cytoplasmic sperm injection); 64 embryos were transferred to the women. More than one embryo was transferred to each patient because IVM is known to have lower rates of implantation. The resulting pregnancies were singleton pregnancies, with the exception of one, which started as twins but became a singleton pregnancy due to spontaneous reduction.

Dr Holzer said he believed that adjusting the media in which the immature oocytes were matured in the laboratory was probably responsible for the improved success rate as the trial progressed.

“Fertility preservation is of the utmost importance to patients undergoing treatments that have the potential of making them infertile. Our research shows that it is possible to collect immature oocytes from unstimulated ovaries, mature them in vitro, freeze and thaw them and then achieve pregnancies and live births, without the risk of aggravating the patients’ hormone-sensitive disease, delaying their treatment for cancer or re-instituting a metastatic malignant disease,” he concluded.

Notes:

[1] The McGill Reproductive Center is led by Professor Seang Lin Tan and the scientific director is Professor Ri-Cheng Chian. They are both pioneers in the in vitro maturation of human oocytes and have developed the “McGill oocyte and embryo vitrification method” using the Cryoleaf system, which is now licensed to Medicult.

Emma Mason | EurekAlert!
Further information:
http://www.eshre.com

Further reports about: Preservation Stimulation VITRO fertility infertile oocyte pregnancies

More articles from Life Sciences:

nachricht For a chimpanzee, one good turn deserves another
27.06.2017 | Max-Planck-Institut für Mathematik in den Naturwissenschaften (MPIMIS)

nachricht New method to rapidly map the 'social networks' of proteins
27.06.2017 | Salk Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>