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!
Some brain tumors may respond to immunotherapy, new study suggests
11.12.2018 | Columbia University Irving Medical Center
Climate change and air pollution damaging health and causing millions of premature deaths
30.11.2018 | International Institute for Applied Systems Analysis (IIASA)
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
14.12.2018 | Power and Electrical Engineering
14.12.2018 | Physics and Astronomy
14.12.2018 | Physics and Astronomy