This is a bit of a shock:

IVF boosts birth defect risk by 40 percent
By Clara Pirani
January 28, 2005
From:

BABIES conceived through IVF are up to 40 per cent more likely to suffer birth defects including cleft palate, spina bifida and heart problems.
Researchers at the Telethon Institute for Child Health Research in Perth analysed 25 studies from around the world and concluded that IVF babies consistently showed a 25 to 40 per cent greater risk of abnormalities. However, the researchers do not know why the birth defects are more common among IVF babies.
Researcher Michelle Hansen said the defects could be caused by the IVF procedure, or couples who struggle to become pregnant could have an underlying medical condition that caused birth defects.
"We don't know why yet, because it's very difficult to tease out the fact they come in with an underlying cause of infertility anyway," Ms Hansen told The Australian.
"It would be a lot easier if a fertile couple had IVF, because then we could work out if it was just the treatment, or if it was something to do with an underlying disease. At the moment we don't know.
"Other causes could be something to do with the treatment itself, the way the egg, sperm or embryo are manipulated, or the medications that are given to induce ovulation or to sustain pregnancy."
Monash IVF's medical director Gab Kovacs said previous studies had shown women who had trouble getting pregnant had a higher risk of having babies with birth defects.
"We've already shown that people who have got fertility problems, or sub-fertility as it's known, are poor reproducers," Professor Kovacs said. "Many years ago we did a paper on people who had ovulation problems and their abnormality rate was already up."
Ms Hansen said anyone considering IVF should be warned about the increased risks. "I think in the past couple of years it has become quite standard practice for clinics to at least mention the research that has come out from WA and a few other places," she said.
"And now this paper will make it even more accepted that they really need to provide this information so patients are giving informed consent when they undertake such treatment."
The same researchers released a study in 2002 claiming the incidence of abnormalities in IVF babies was twice the level for those who were conceived naturally.
"But now we've pooled research from all around the world, we found it's supported our findings that there is an increased risk, but it is lower than we previously thought," Ms Hansen said.
Professor Kovacs said although there was an increased risk of defects, it was not substantial. He said about 3 per cent of babies who are conceived naturally would have birth defects.
"We have to put it into perspective," he said.
"If the basic risk is about 3 per cent, then even if there's a 30 to 40 per cent increase through IVF, that means there will be four out of 100 babies, instead of three out of 100 with abnormalities.
"And some of the abnormalities are quite insignificant, things that don't really affect quality of life."
About 5000 Australian babies a year are born using some form of IVF, about 2 per cent of total births.
Ms Hansen said the institute would continue its research to try to determine what was causing the defects.
The study will be published in the journal Human Reproduction next month.