Children conceived by assisted reproductive technologies, such as IVF, are at a slightly higher risk of dying within the first year of life than children conceived naturally, according to a recent study in Sweden.
For children aged one to 18 years, mortality rate was similar regardless of the method of conception.
'It is important to note that even if we on a group level can see a somewhat increased risk of infant mortality after IVF, the absolute risk for each individual is still very small', said corresponding author of the study Dr Kenny Rodriguez-Wallberg, from the Department of Oncology and Pathology at Karolinska Institutet. 'It is also reassuring to know that there is no increased risk of mortality in this group of children beyond the first year of life.'
The researchers analysed patient records for over 2.8 million births in Sweden. Of these, 43,506 children were conceived by assisted reproductive technologies. Within the first year of life, 7,235 died, of whom 114 were conceived as a result of assisted reproduction.
After adjusting for confounding factors such as the mother's age and earlier infertility, the researchers found that the children conceived through assisted reproduction had a 45 percent higher risk of death before one year of age than children conceived naturally. The researchers link this higher rate to increased likelihood of being born prematurely among children conceived by assisted reproductive technologies.
The risk varied depending on which type of assisted reproduction was used, and was highest in the first week after birth. During this first week, children conceived by transfer of a frozen embryo had over double the risk of death than children conceived naturally. However, this was based on a very small sample of only four children born from frozen embryos, and the risk reduced to the same level as children conceived naturally after the first week.
Children conceived via fresh embryo transfer or via intracytoplasmic sperm injection (ICSI) did not have an increased mortality rate in the first week compared to naturally conceived children.
'Our results indicate that the kind of assisted reproductive technique used may make a difference, and therefore it is important to further investigate what causes or underlying mechanisms are behind the risks,' said co-author Dr Anastasia Nyman Iliadou from the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet. 'They also show the need for extra attention and care of children conceived with IVF, especially during the first week of life.'