The academic performance of teenagers who were conceived through assisted reproductive technologies (ART) is the same as that of their peers, according to Danish doctors.
The study, which was reported at the annual meeting of the European Society of Human Reproduction and Embryology in Lisbon, Portugal, is the first large national study to look at the high-school test scores of children conceived through ART.
'These findings are very important for infertile patients,' said Anne LÃ¦rke Spangmose Pedersen, a medical student at the Copenhagen University Hospital Hvidovre in Denmark, who presented the findings. 'The higher rate of twins, and preterm birth in ART singletons, might have given rise to lower academic test scores. But our results now confirm smaller studies which have shown no difference in IQ between ART and non-ART children.'
In Denmark every ninth-grade student (aged 15-16) must sit a national standardised test. This study looked at the test scores of every child conceived by ART born between 1995 and 2000 - a total of 8,251, comprising 4,991 singletons and 3,260 twins. They compared them with the scores of every twin born in Denmark at that time - more than 10,000 children - and a randomly selected group of singletons conceived naturally.
The raw results showed that ART singletons performed slightly better, with test scores averaging 7.71, than naturally conceived singletons, who scored an average of 6.75. Similarly, ART twins scored higher, averaging 7.19 on the test, than naturally conceived twins, who scored an average of 6.78. However, after adjusting the scores for factors including maternal age, birthweight, gestational age and socioeconomic status, these differences all disappeared.
'All our four study groups had test scores very close to the average, which is reassuring,' said Pedersen.
Several studies have found more pregnancy complications after ART - usually as a result of multiple births leading to prematurity and low birthweight, but some studies had also found these increased risks in singleton pregnancies following ART. So there has been concern about the long-term effects of ART on these children. A few smaller studies have examined the effect of ART on children's IQ and also found no differences, but this was the first to look at children near the end of their school years.
Stuart Lavery, a consultant gynaecologist at Hammersmith Hospital who was not involved in the study, said that parents should find these results reassuring. 'From a scientific perspective, and also from a social perspective, these children are no different from any others.'
Around five percent of children in Denmark are now conceived through ART, such as IVF, and Pedersen stressed that further analysis was needed, including checking factors that were not looked at in the study - such as family stability and the parents' own educational background. 'ART is still associated with a slightly increased risk of congenital malformations and prematurity, and we should continue to survey our ART children as new developments in technique... are always being introduced,' she cautioned.