Belgian researchers have revealed that an embryo screening test called pre-implantation genetic diagnosis (PGD) is safe and no issues are seen with single pregnancies. However if the test is carried out in multiple pregnancies, the mortality rates were high.
The study examined 581 children born at one Belgian centre over 13 years. All children had been screened using PGD. Among these children, it was found that rates of birth defects and deaths were similar to that of other IVF procedures. The researchers compared the rate of defects in these children to 2,889 children born using IVF, who were not screened.
3.38% of the latter group had birth defects as compared with 2.13% of PGD children. Death rates in both groups were 1%, but in multiple pregnancies PGD kids had a death rate of over 11% compared with just 2.3% in the other group.
"At present, we don't have an explanation for why the perinatal death rate (for multiple pregnancies) should be so much higher in the PGD children, and we need to be careful about drawing firm conclusions from these observations as they may be biased due to low numbers," said Professor Inge Liebaers, head of the centre for medical genetics at the University Hospital Brussels.
The details appear in the journal Human Reproduction.