CDC: IVF May Boost Birth Defects Risk
Certain Birth Defects May Be More Common in Babies Conceived Through In Vitro Fertilization or Intracytoplasmic Sperm Injections
Nov. 17, 2008 -- The CDC reports that certain birth defects -- including
heart wall problems and cleft lip/palate -- may be two
to four times more common among babies conceived with assisted reproductive
technology (ART) than babies conceived naturally.
Those findings -- published in the advance online edition of Human
Reproduction -- focus on in vitro fertilization (IVF) and intracytoplasmic
sperm injection (ICSI).
ART is becoming more common, but the CDC isn't making any recommendations
about its use.
"Today, more than 1% of infants are conceived through ART and this
number may continue to increase," CDC epidemiologist Jennita Reefhuis, PhD,
says in a news release.
The chances of birth defects in a baby conceived through ART are
"low," notes Reefhuis.
But she says "it is still important for parents who are considering
using ART to think about all of the potential risks and benefits of this
ART and Birth Defects Study
Reefhuis and colleagues reviewed data from mothers of about 13,500 babies
born with birth defects and mothers of more than 5,000 babies without birth
Those babies were born from October 1997-December 2003 in 10 states
(Arkansas, California, Georgia, Iowa, Massachusetts, New Jersey, New York,
North Carolina, Utah, and Texas).
About 1% of the babies without birth defects were conceived through ART,
compared to 2.4% of the babies with birth defects, according to interviews with
The following types of birth defects were more common among babies conceived
- Septal heart defects: Twice as common among babies conceived by
- Cleft lip and/or cleft palate: 2.4 times as common among babies
conceived by ART
- Esophageal atresia (birth defect of the esophagus): 4.5 times more
common among babies conceived by ART
- Anorectal atresia (birth defect in the anal/rectal area): 3.7 times
more common among babies conceived by ART
Those findings, which take into account other risk factors, only applied to
single births, not to twins, triplets, or other
But the CDC points out that multiple births are associated with ART and with
"Thus, ART might contribute to the risk of major birth defects both
directly by increasing the risk of defects among singletons, and indirectly by
increasing the occurrence of twinning which is a strong risk factor for many
types of major birth defects," the study states.
The study doesn't prove that ART was to blame for the birth defects.
"Subfertile women might have a higher risk of having a child with a
birth defect regardless of whether infertility treatments are
used," write Reefhuis and colleagues.
The CDC also notes that birth defects are rare and that the findings in the
new study need to be checked.
WebMD asked Elizabeth
Ginsburg, MD, president of the Society for Assisted Reproductive Technology and
medical director of assisted reproductive technologies at Brigham and
Women's Hospital in Boston, about the new CDC report.
Ginsburg points out that the study
included a small number of babies conceived through ART and that the study
doesn't settle key questions about ART and birth defects.
"We've been counseling
patients with infertility for a very long time that we don't know whether
there's an increased risk of adverse outcomes for their
baby," Ginsburg tells WebMD.
Ginsburg notes that some studies
-- but not all -- link ART to poor outcomes for babies, but it's still not
clear whether ART or infertility are to blame. "I think there are enough
[studies] to say there may be something to it," but It's
"unsettling" to have those issues unresolved.