The report is based on a study conducted by researchers from University of Adelaide and published in the New England Journal of Medicine. They reviewed 309,000 births in South Australia. 1,878 of these resulted from ICSI treatment. The risk of a birth defect after natural conception was 5.8 per cent compared with 7.2 per cent following IVF and 9.9 per cent, according to their analysis.
ICSI technology has been available for around 20 years. It is important to note that this is not the first research study to look into the link with birth defects. Several meta-analyses (critical review of several good quality research pooled together – which is the gold standard for quality evidence), have shown conflicting results. Some suggest increased risks of abnormality with ICSI vs. IVF, and others have shown no difference in risk.
Researchers in this study did not determine whether the risks of abnormalities were a result of the ICSI technique or because men with lower sperm counts were more likely to pass on anomalies.
“It may well be that the families who have to use ICSI have extreme sperm damage, and this may be why there is a higher rate of anomalies in this group,” said Professor Peter Illingworth, an associate professor at the University of Sydney.