IVF and ICSI linked to birth defects and low birth weight

Two studies of babies conceived using in IVF (vitro fertilisation) and ICSI (intracytoplasmic sperm injection) were published in the New England Journal of Medicine last week. One of the studies reports that children have an increased risk of birth defects and the other shows that low birth weights are more common in these children.

In the first study, a team of researchers based at the University of Western Australia examined data from the births register, comparing 1138 babies born from assisted reproduction with 4000 naturally conceived children. They discovered that nine per cent of singleton IVF and ICSI babies not born prematurely had 'major birth defects', compared to just over four per cent of naturally conceived children. The birth defects include heart problems, Down's syndrome, club foot and cleft lips and palates.

The second study compared 42,463 American babies born between 1996 and 1999 following assisted reproduction techniques, with over 3 million other children. The researchers, from the Centre of Disease Control and Prevention in the US, found that six-and-a-half per cent of the assisted reproduction children had a low birth weight (below 5.8 pounds), more than double the number of low birth weights in naturally conceived children.

Dr Jennifer Kurinczuk, a lead author in the Australian study, called for more research into the findings, as previous studies have not produced such results. She said there could be a number of reasons why birth defects were more common in IVF and ICSI children, including genetic abnormalities in the parents, which may affect their fertility, or problems associated with the age of the parents. She did not rule out the possibility that they may be caused by the procedures themselves. But she said that the studies should not cause alarm, adding 'what we have to remember is that more than 90 per cent of babies are free of such major defects'.