New Australian research into the risks of babies being born with abnormalities suggests that parents who use assisted conception methods may need to be more selective about the type of treatment they choose.
A common form of in vitro fertilisation (IVF) used in situations where men have a lower sperm count has been linked with a much higher risk of birth defects.
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Scientists from the Robson Institute at the University of Adelaide, South Australia, looked at 309,000 cases, which included a sample of natural births and ones using various methods of assisted conception. 1,878 of those cases involved intracytoplasmic sperm injection (ICSI).
The technique of ICSI involves the sperm being injected directly into the egg before implantation. It differs from traditional forms of IVF when both sex cells are combined in a petri dish and the sperm is then allowed to infiltrate the egg on its own accord.
The rate of birth defects among naturally conceived babies was recorded at approximately 5.8 per cent, and researchers found that this increased significantly when assisted conception was involved.
For babies conceived through traditional IVF, the rate of birth abnormalities was 7.2 per cent, with that figure jumping to 9.9 per cent for pregnancies where the ICSI method was involved.
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"Treatment with assisted reproductive technology was associated with increased risks of cardiovascular, musculoskeletal, urogenital, and gastrointestinal defects and cerebral palsy," the researchers wrote, adding, "there were no significant associations between assisted conception and the risk of any recorded syndrome (Down's, Edward’s, Patau's, Pierre Robin's, Turner, or Klinefelter syndromes), although these conditions were rare."
Professor Peter Illingworth, associate professor at the University of Sydney suggested that it may not be the technology itself that is the cause of such high rates of defects among ICSI-assisted births.
"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," he said.
The study was jointly funded by the National Health and Medical Research Council and the Australian Research Council, and was published in The New England Journal of Medicine on May 5, 2012.
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