Good results with only one egg in in-vitro fertilization

December 02, 2004

Nearly as many women who received only one embryo at a time gave birth as women who received two embryos. At the same time the risk of giving birth to twins is minimized. These are the findings of a major study from the Sahlgrenska Academy, at Göteborg University in Sweden.

In-vitro fertilization, IVF, is a successful method to help childless couples to become parents. To maximize the chance of pregnancy, physicians have generally reintroduced more than one embryo. This has led to a considerably larger proportion of multiple births compared with spontaneous pregnancies. Multiple birth means two or more children in the same pregnancy, most often twins. Expecting more than one child entails greater risk. These children are often born prematurely and often have low birth weight. To reduce the number of pregnancies with more than one child, the Swedish National Board of Health and Welfare recommends that only one embryo be transferred at a time.

In the world's largest controlled study, scientists at the Sahgrenska Academy in Gothenburg have compared deliveries in two groups of women who underwent IVF. Half of the women first had one embryo transferred. If it did not develop, they received a second embryo that had been kept frozen until it was reintroduced. The other half of the women received two embryos from the beginning. The study comprised 661 women under the age of 36 from 11 clinics in Scandinavia.

"The results show that there were nearly as many deliveries in both groups: 42.9 percent of the women in the two-embryo group gave birth, compared with 38.8 percent of the single-embryo group," says Professor Christina Bergh and specialist physician Ann Thurin, who were in charge of the study.

The great benefit is that the proportion of deliveries with twins or more siblings was minimal in the group of women who received one embryo at a time.

"In the single-embryo group, 0.8 percent of the deliveries were multiple, compared with 33.1 percent of deliveries in the two-embryo group," say the researchers.

In Scandinavia single-embryo reintroductions are already a routine at many clinics. "The study findings will hopefully hasten developments toward the introduction of one embryo at a time in other parts of the world," says Christina Bergh.

The studies findings are being published on December 2. 2004, in the prestigious American medical journal The New England Journal of Medicine.

Brief facts about IVF/In-Vitro Fertilization In IVF eggs are taken from the woman's ovaries. The eggs are placed in a nutrient solution together with sperm. Those eggs that become fertilized can be returned to the woman and develop there into a fetus. Embryos of good quality can be preserved frozen and be transferred to the woman in the same way, after thawing.

The world's first successful IVF was carried out in the United Kingdom in 1978, and since then around one million IVF children have been born around the world. Scandinavia's first successful IVF was performed at Sahlgrenska Hospital in Gothenburg in 1982. In Sweden some 2,500 children per year are born as a result of successful IVF-treatment.
-end-
For more information, please contact:

Adjunct Professor Christina Bergh, phone: 46-31-342-3795, cell phone: 46-736-88-9325, e-mail: christina.bergh@vgregion.se The Sahlgrenska Academy at Göteborg University, Department of Women's and Children's Health, Section for Obstetrics and Gynecology.

Journal: The New England Journal of Medicine, 351:23, December 2, 2004 Name of article: "Elective single embryo transfer versus double embryo transfer in in-vitro fertilization"
Authors: Ann Thurin, Jon Hausken, Torbjörn Hillensjö, Barbara Jablonska, Anja Pinborg, Annika Strandell, and Christina Bergh

Swedish Research Council

Related Embryos Articles from Brightsurf:

Zebrafish embryos help prove what happens to nanoparticles in the blood
What happens to the nanoparticles when they are injected into the bloodstream, for example, to destroy solid tumours?

Artificial intelligence system developed to help better select embryos for implantation
Investigators from Brigham and Women's Hospital and Massachusetts General Hospital are developing an artificial intelligence system with the goal of improving IVF success by helping embryologists objectively select embryos most likely to result in a healthy birth.

Embryos taking shape via buckling
The embryo of an animal first looks like a hollow sphere.

Who's your daddy? Male seahorses transport nutrients to embryos
New research by Dr Camilla Whittington and her team at the University of Sydney has found male seahorses transport nutrients to their developing babies during pregnancy.

Study suggests embryos could be susceptible to coronavirus
Genes that are thought to play a role in how the SARS-CoV-2 virus infects our cells have been found to be active in embryos as early as during the second week of pregnancy, say scientists at the University of Cambridge and the California Institute of Technology (Caltech).

Spawning fish and embryos most vulnerable to climate's warming waters
Spawning fish and embryos are far more vulnerable to Earth's warming waters than fish in other life stages, according to a new study, which uniquely relates fish physiological tolerance to temperature across the lifecycles of nearly 700 fish species.

Animal embryos evolved before animals
A new study by an international team of researchers, led by scientists from the University of Bristol and Nanjing Institute of Geology and Palaeontology, has discovered that animal-like embryos evolved long before the first animals appear in the fossil record.

Choosing the best embryos
Struggling with infertility? You are not alone. Infertility affects one out of every six Canadian couples.

Turtle embryos play a role in determining their own sex
In certain turtle species, the temperature of the egg determines whether the offspring is female or male.

Early in vitro testing for adverse effects on embryos
ETH researchers have combined embryonic cells and liver cells in a new cell culture test.

Read More: Embryos News and Embryos Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.