High rates of birth defects associated with an artificial reproductive technology: Study

By Dr. Ananya Mandal, MDMay 8 2012

A new study has shown that one of the most popular forms of IVF could double the risk of birth defects.

Researchers found that one in ten babies born through ICSI suffered some form of abnormality. This compares with just over one in 20 of those conceived naturally. It is unclear yet whether the problems are caused by the treatment, or the fact couples having it are at higher risk of defects anyway.

ICSI – or intracytoplasmic sperm injection – is used to treat male infertility. It involves injecting a sperm directly into an egg with a fine glass needle. More than 23,000 procedures were performed last year and it represents just over half of all IVF treatments. ICSI can help couples who were previously unable to conceive because the man’s sperm count was low or they were of too poor quality to swim up to the egg.

The new study was published in the New England Journal of Medicine. In this the researchers from the University of Adelaide in Australia looked at more than 300,000 births. They found that babies born via ICSI were 57 per cent more likely to suffer some form of abnormality. These ranged from serious defects of the heart and digestive system to relatively minor abnormalities such as club feet that could be fixed with surgery. Overall 9.9 per cent of babies born through ICSI had a defect compared with 5.8 per cent of those born naturally.

They also noted that standard IVF – where semen containing thousands of sperm is placed in a dish with eggs – was found to be no more risky than natural conception, once the couple’s age and other factors had been accounted for. Experts are unsure whether it is the treatment causing the defects or the poor quality sperm of the men.

Lead author Professor Michael Davies, from the University of Adelaide, said, “We know from the study that standard IVF is safe. But we also now know that with ICSI, the risk is sky high.” He said the technique involved implanting faulty sperm into an egg – in nature these would be weeded out.

The study's co-author, Eric Haan, said the key finding was the increased risk of birth defects associated with ART. “In our study we were able to tease out where some of these risks lie,” he said. “It turned out the main source of risk lies in whether you freeze or don't freeze the embryos.” “When comparing fresh IVF and ICSI, IVF was 36 per cent less likely to result in birth defects than ICSI,” he said. “However, when the embryos were frozen, the risks of birth defects in both procedures decreased significantly,” he said.

Dr Allan Pacey, fertility expert at the University of Sheffield and chairman of the British Fertility Society, said, “An important point to make is that we know that babies conceived naturally to couples previously diagnosed with infertility are also  at slightly higher risk, which suggests that it may be something to do with the “infertility” rather than the “technology” used to conceive them…It should be stressed that the vast majority of babies born  are healthy and the actual risks of any problems being detected are small.”

Professor Peter Illingworth, of the University of Sydney, said, “It may well be that the sort of families who have to use ICSI have extreme sperm damage, and this may be the explanation as to why there is a higher rate of congenital abnormalities.”

Professor Haan said it was also important to look at background factors when assessing risk. “Even when you don't use ART, you're at increased risk of birth defects anyway, just because you are infertile…Assisted pregnancies only increase the risk by a relatively small amount. You're not suddenly going to go from low risk to high.”

The inventor of ICSI, André van Steirteghem, around a couple of years back, warned it was being overused. Professor Steirteghem – who invented it in Belgium in 1991 – told a conference that it should only be used as a last resort as it may cause problems in children.

Clare Lewis-Jones, of leading patient charity, Infertility Network UK, said, “IVF and ICSI bring joy to tens of thousands of people every year – last year there were around 60,000 cycles of IVF in the UK and without this many couples would never experience the joy of having a child of their own. If patients are concerned by this research, I would recommend they speak directly to their clinician who will be able to discuss their individual situation.”