PHILADELPHIA -- Children conceived through in vitro fertilization do not have higher rates of cancer, malformations, or psychological or developmental delays, according to preliminary findings of the largest literature review on the subject to date.
Still, singleton IVF babies are at increased risk for premature birth (OR 1.95), perinatal mortality (OR 2.18), and very low birth weight (OR 2.7), compared singletons conceived naturally, reported Kathy Hudson, Ph.D., who is the director of the Genetics and Public Policy Center at Johns Hopkins University in Washington, D.C., which conducted the study.
IVF twins are at no greater risk than naturally conceived twins for these adverse outcomes, she said at the annual meeting of the American Society for Reproductive Medicine.
In addition, the study found evidence "suggestive [of] but not sufficient" to indicate that assisted reproductive technologies (ART) may increase the risk of two rare genetic disorders, Beckwith-Wiedemann syndrome and a form of Angelman's syndrome.
"We think this is of some concern and that it needs extra follow-up," said James Mills, M.D., an investigator in the study and chief of the pediatric epidemiology section of the National Institute of Child Health and Human Development.
Beckwith-Wiedemann syndrome occurs in about 1 in 15,000 births in the general population, and the specific form of Angelman's syndrome that is of concern--an imprinting defect--occurs even more rarely, in about 1 in 300,000 births. Thus, even though these conditions appear to occur four to seven times more commonly among ART children, their incidence remains rare, even in this population, Dr. Mills said.
The researchers undertook a systematic review of 169 published studies examining neonatal outcomes; malformations; genetic anomalies; cancer; and psychosocial, developmental, and health outcomes in ART children aged 1 year or older.
"There have been small studies suggesting increases in cancers and malformations and psychosocial delays in these children, so what we have found should be very comforting and reassuring to parents," Dr. Hudson said.
The study was cosponsored by the American Academy of Pediatrics and the American Society for Reproductive Medicine.
ARTICLES BY KATE JOHNSON
COPYRIGHT 2004 International Medical News Group
COPYRIGHT 2005 Gale Group