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New study links birth defects with fertility treatments

16 February 2007
Appeared in BioNews 395

Contrary to some earlier findings, a large Canadian study links an increase in birth defects with babies born through fertility treatments. According to the results of the study, which was presented at a Society for Maternal-Fetal Medicine meeting in San Francisco, the overall risk appears minimal - less than three per cent for assisted conception versus less than two per cent for natural conception - but the risks for specific birth defects were notably higher. Dr Mark Walker, one of the study's leaders, hoped that people would find the results 'reassuring' because 'the absolute risks are still low'.

The study, conducted at the University of Ottawa, is the largest of its kind in North America and it compares the outcomes of 61,208 pregnancies in Ontario during 2005. Five per cent of the total births were a result of fertility treatments.

Dr Nancy Green, medical director of the March of Dimes, said the study was an important first because it comprehensively quantified specific birth defects while taking the effects of other potential causal factors such as age, smoking, gender of the babies and birth complications into account when estimating risk rates.

The study found that the greater the complexity of the fertility treatment, the higher the risk. Assisted reproduction technologies (ART) like IVF had the highest risk and the administration of ovulation-stimulating medications had the lowest.

Babies conceived through ART were almost nine times more likely to have gastrointestinal disorders, such as abdominal wall defects or abnormally located organs. The risk of cardiovascular disorders was more than double and although there was no increased risk for spina bifida and facial defects like cleft palate, the risk of malformed limbs and other deformities was slightly elevated. The study's head researcher, Darine El-Chaar, commented, 'We think this should become part of counselling couples that are infertile, especially that the degree of manipulating the egg and sperm may affect the risk of defects.'

It is already known that pregnancies achieved through ART face a higher risk of premature births and complications such as high blood pressure, diabetes and placental problems. Although previous studies found that ART babies are not at any more risk of major health problems than naturally conceived children, some studies have linked IVF to a slightly increased risk of certain rare genetic conditions caused by faulty genetic imprinting, such as Beckwith Wiedmann syndrome.

Fertility treatment may raise birth defect risk
The Daily Mail |  9 February 2007
19 November 2012 - by Dr Nicola Davis 
Infants conceived by IVF are at significantly greater risk of birth defects compared to naturally conceived babies, announced scientists at a conference last month...
23 February 2009 - by Sarah Pritchard 
A large study has investigated the potential genetic risks to children conceived by in vitro fertilisation (IVF). It confirms earlier research indicating that babies born following assisted conception have a small increased risk of certain genetic health problems. The New York Times reports that in November last...
4 August 2008 - by Dr Rebecca Robey 
The increased risk of complications during pregnancy and at birth observed in babies conceived through assisted reproductive technology (ART) may be the result of parent's underlying infertility problems rather than the technology itself, a new study has revealed. In a report published in The Lancet, researchers found...
3 November 2005 - by BioNews 
Babies conceived using fertility treatments, including IVF, are at no more risk of birth defects than naturally conceived infants, a large US study shows. Researchers at Stamford Hospital in Connecticut looked at data from over 36,000 pregnancies, around five per cent of which arose following fertility treatments. But their findings...
20 October 2005 - by BioNews 
Around half of all the eggs produced by both older and younger women could have genetic errors, three new US studies suggest. The findings, reported at the annual meeting of the American Society for Reproductive Medicine (ASRM) in Montreal, Canada, have lead to calls from some fertility experts to screen...
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