May 5, 2012

expert reaction to new research into risk of birth defects to babies born using reproductive technologies

The New England Journal of Medicine published a paper which showed that an increased risk of birth defects linked with use of reproductive technologies was generally not due to treatment, but rather due to underlying factors, while unexplained differences in risk varied across different treatments.

Dr Allan Pacey, fertility expert at the University of Sheffield and Chairman of the British Fertility Society, said:

“This is an interesting paper which analyses the register of birth defects in South Australia with the data from clinics providing infertility treatments such as IVF and ICSI. This is with the aim of trying to find any links between the two, a common approach in this kind of work requiring large numbers of patients to make sure any statistical associations are robust.

“Several links are found by the authors, but these largely confirm what is already known and suggest that whilst babies born from IVF are as healthy as their naturally conceived counterparts, there is still some residual risk to babies born through ICSI that currently cannot be explained. An important point to make is that we know that babies conceived naturally to couples previously diagnosed with infertility are also at slightly higher risk which suggests that it may be something to do with the ‘infertility’ rather than the ‘technology’ used to conceive them..

“Couples undergoing assisted conception are understandably concerned about the potential health of any babies born and studies like this are enormously helpful in giving them accurate information and helping to put the risk into context. It should be stressed that the vast majority of babies born are health and the actual risks of any problems being detected are small.”

Professor Peter Illingworth, Medical Director at IVF Australia and an Associate Professor with the University of Sydney, said:

“This paper confirms the previously widely reported association between babies being conceived through assisted reproduction technologies (ART) and having a slightly higher risk of congenital anomalies. These findings are consistent with previously widely reported data in this area. What is new about this paper is that Professor Davies has, for the first time, looked at other women in similar situations.

“The big question underlying the association between assisted reproduction and congenital anomalies is whether this is due to the laboratory process itself, or whether it’s a reflection of the fact that people who have to use ART to have their family already have pre-existing damage to their eggs and sperm that puts them at higher risk of having children with congenital anomalies.

“Professor Davies’ findings suggest the later explanation. He has, for the first time, looked at the siblings who have been conceived normally of children who have been conceived from ART. He has also looked at women who have presented to antenatal clinics with a past history of infertility but who have not had ART. Both of these groups show a very similar effect, with a higher risk of congenital anomalies, as do the children who have been conceived using ART. This is a new finding.

“The other interesting feature about his results is the fact that, when he separates the two types of ART into IVF and intra-cytoplasm sperm injection (ICSI), his findings are that IVF children do not have a higher risk of congenital anomalies and that the risk is limited to children who have been conceived using ICSI. This is contrary to other findings in large studies in Europe. The explanation for this is not at all clear. It may well be that the sort of families who have to use ICSI have extreme sperm damage, and this may be the explanation as to why there is a higher rate of congenital anomalies in this group.

“I think this is a very important paper; it’s one that we’ve needed for a long time. I think Professor Davies should be congratulated on his work”

‘Reproductive Technologies and the Risk of Birth Defects’, Davies et al., published in the New England Journal of Medicine on Saturday 5 May 2012.