The study was conducted by Dr. William Gibbons, director of The Family Fertility Program at Texas Children's Hospital and professor of obstetrics and gynecology at Baylor College of Medicine, along with colleagues at the Society for Assisted Reproductive Technologies (SART) Marcelle Cedars, MD and Roberta Ness, MD.
They reviewed three years of data that compared average birth weight and gestational time for single births born as a result of standard IVF, IVF with donor eggs and IVF with a surrogate. While the ability to achieve a pregnancy is tied to egg/embryo quality, the obstetrical outcomes of birth weight and length of pregnancy are more significantly tied to the uterine environment that is affected by the reason the woman is infertile.
There were more than 300,000 IVF cycles during the time of the study producing more than 70,000 singleton pregnancies.
"This is the first time that a study demonstrated that the health of a women's uterus is a key determinant for a fetus to obtain normal birth weight and normal length of gestation," said Dr. Gibbons. "While obvious issues of uterine fibroids or conditions that alter the shape of the uterus are suspected to affect pregnancy rates, conditions that result in poorer ovarian function to the point of needing donor eggs are not known. Further research is needed to fully understand this complex issue."
As assisted reproductive technologies (ART) in the U.S. mature, increasing attention is directed not just to pregnancy rates but also to the obstetrical outcomes of those resulting pregnancies – meaning the newborn's birth weight, health and gestational age. Currently, about one percent of U.S. births are the result of ART therapies such as IVF, donor eggs, intracytoplasmic sperm injection, embryo cryopreservation, embryo donation, preimplanation genetic diagnosis, and male infertility surgery and medical therapy.
The study explored several scenarios and found that the birth weight associated with standard IVF – in which the patient carried the embryo created with her own egg – was greater than that associated with donor egg cycles, and less than that in gestational carrier cycles. This finding held true even when other factors were considered showing that the woman's own uterus may be a determining factor.
Gibbons said the study also determined that a diagnosis of male infertility did not affect birth weight or gestational age, yet every female infertility diagnosis was associated with lower birth weight and a reduced gestational age.
Patients diagnosed with a uterine health issue, such as fibroids or other factors, had babies with the lowest birth weights and gestational ages. This led the researchers to examine the uterine environment as it relates to the type of therapy being considered.
Gibbons explains that in standard IVF, an embryo is transferred to a woman who has just undergone controlled ovarian hyperstimulation, while in donor egg IVF and gestational carrier IVF, the embryo is transferred to a "natural" or unstimulated uterus. Then, the researchers looked at IVF utilizing frozen embryo transfer in which an embryo created with a patient's own egg is transferred to her own unstimulated uterus. They found that babies born of frozen embryo transfer cycles had markedly greater birth weights than those born as a result of standard IVF.
"That finding may help women seeking pregnancy and their physicians to consider frozen embryo transfer as a possible option if the uterine health is not a consideration," said Gibbons. "This study shows us how so many factors are related to a successful outcome and we continue to learn where further research may be needed."
The complete study, called "Toward understanding obstetrical outcome in advanced assisted reproduction: varying sperm, oocyte and uterine source and diagnosis," can be found at Fertility and Sterility at www.fertstert.org.
About Texas Children's Hospital
Texas Children's Hospital is committed to a community of healthy children by providing the finest pediatric patient care, education and research. Renowned worldwide for its expertise and breakthrough developments in clinical care and research, Texas Children's is nationally ranked in all ten subspecialties in U.S. News & World Report's list of America's Best Children's Hospitals. Texas Children's also operates the nation's largest primary pediatric care network, with more than 40 offices throughout the greater Houston community. Texas Children's has embarked on a $1.5 billion expansion, Vision 2010, which includes the Jan and Dan Duncan Neurological Research Institute, a comprehensive obstetrics facility focusing on high-risk births and a community hospital in suburban West Houston. For more information on Texas Children's Hospital, go to www.texaschildrens.org. Get the latest news from Texas Children's Hospital by visiting the online newsroom and on Twitter at twitter.com/texaschildrens.
Christy Brunton | EurekAlert!
Amputees can learn to control a robotic arm with their minds
28.11.2017 | University of Chicago Medical Center
The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
11.12.2017 | Information Technology
11.12.2017 | Power and Electrical Engineering
11.12.2017 | Event News