Skip to content

Infertility & Reproduction Health Center

Font Size

IVF Risks Mostly Due to Multiple Births

Single-Embryo Transfer May Cut Risk of in Vitro Fertilization
By
WebMD Health News
Reviewed by Louise Chang, MD

July 26, 2007 -- In and of itself, IVF -- in vitro fertilization -- carries only slight risks compared with natural conception, a new study suggests.

IVF does carry major risks, which include premature birth, low birth weight, stillbirth, spontaneous abortion, preeclampsia, placenta previa, and, to a lesser extent, birth defects and cerebral palsy.

What is responsible for these poor outcomes? To find out, Alastair G. Sutcliffe, MD, of the Institute of Child Health at the University College London, and Michael Ludwig, MD, of the Center for Hormonal and Metabolic Illnesses in Hamburg, Germany, analyzed 30 years of data on IVF.

The main finding: Most IVF risks are due to multiple births, and not to the IVF procedure itself. Twins, triplets, and other multiple-birth children are at much higher risk of premature or low birth weight than are singleton children. And premature birth and low birth weight are linked to a host of health risks.

But even single children born via IVF have more health risks than do naturally conceived children. Nearly all these risks, the researchers find, are due to the same parental factors -- such as older age or genetic defects -- that make it difficult for a couple to conceive naturally.

"The things related to subfertility are probably the factors that result in the subtle differences in children born via assisted reproduction technology and children naturally conceived," Sutcliffe tells WebMD.

The findings closely mirror those of an expert panel convened in 2005 by the U.S. National Institute of Child Health and Human Development. NICHD medical officer Uma M. Reddy, MD, MPH, was lead author of the panel's report.

"The majority of problems we see with assisted reproductive technology are multiple births," Reddy tells WebMD. "But even singletons have higher risk of complications. But is it due to the procedure or to factors related to infertility? More and more evidence suggests it is not due to the procedure."

In vitro fertilization doctors agree with this assessment, says George Attia, MD, director of reproductive endocrinology and infertility at the University of Miami Miller School of Medicine.

"Most of the risks don't arise from the technique, but from the background biology of the couple," Attia tells WebMD. "Dr. Sutcliffe is right on the spot."

Single-Embryo Transfer: Answer to IVF Risk?

In the U.S., doctors typically implant two or more embryos, which greatly increases the chance of multiple births -- and greatly increases pregnancy risk.

"The majority of the patients want three or four embryos to be transferred," Attia says. "In the U.S., there is a different mentality. Most of this is not covered by insurance, so they really want to get pregnant on the first try and not have to do this several times. In Europe, where IVF is mostly covered by national health services, there is much more stress on single-embryo transfer."

Today on WebMD

Four pregnant women standing in a row
How much do you know about conception?
Couple with surrogate mother
Which one is right for you?
 
couple lying in grass holding hands
Why Dad's health matters.
couple viewing positive pregnancy test
6 ways to improve your chances.
 
Which Treatment Is Right For You
Slideshow
Conception Myths
Article
 
eddleman prepare your body pregnancy
Video
Conception
Slideshow
 
Charting Your Fertility Cycle
Article
Fertility Specialist
Article
 
Understanding Fertility Symptoms
Article
invitro fertilization
Article
 

WebMD Special Sections