SUMMARY ANSWER The available high- quality evidence indicates that specific treatments may give rise to different effects on cognitive development , with certain treatments , including ICSI , associated with cognitive impairment .
STUDY QUESTION Does  fertility treatment  influence cognitive ability in school aged children , and does the impact vary with the type of treatment ?
WHAT IS KNOWN ALREADY Previous review s of the literature concerning cognitive outcomes among children conceived with medical assistance have concluded that study findings are generally ' reassuring ' , but limited attention has been paid to the quality of this research .
In addition , no review has separately assessed the range of treatment modalities available , which vary in invasiveness , and thus , potentially , in their effects on developmental outcomes .
Fertility treatment and risk of childhood and adolescent mental disorders: register based cohort study
Objective To assess the mental health of children born after fertility treatment  by comparing their risk of mental disorders with that of spontaneously conceived children . Design Prospect i ve register based cohort study . Setting Nationwide register based information from Danish National Health Registers cross linked by a unique personal identification number assigned to all citizens in Denmark . Participants All children born in Denmark in 1995 - 2003 with follow-up in 2012 when the children were aged 8 - 17 ; 33 139 children were conceived after fertility treatment and 555 828 children were born after spontaneous conception .  Main outcome measures Absolute risks and hazard ratios for overall and specific mental disorders estimated with adjustment for potential confounding variables . Estimated association between the risk of mental disorders and subtypes of procedures , hormone treatments , gamete types , and cause of infertility . Results The risk of mental disorders in children born after in vitro fertilisation or intracytoplasmic sperm injection was low , and was no higher than in spontaneously conceived children , except for a borderline significant increased risk of tic disorders ( hazard ratio 1.40 , 95 % confidence interval 1.01 to 1.95 ; absolute risk 0.3 % ) . In contrast , children born after ovulation induction with or without insemination had low but significantly increased risks of any mental disorder ( 1.20 , 1.11 to 1.31 ; absolute risk 4.1 % ) , autism spectrum disorders ( 1.20 , 1.05 to 1.37 ; 1.5 % ) , hyperkinetic disorders ( 1.23 , 1.08 to 1.40 ; 1.7 % ) , conduct , emotional , or social disorder ( 1.21 , 1.02 to 1.45 ; 0.8 % ) , and tic disorders ( 1.51 , 1.16 to 1.96 ; 0.4 % ) . There was no risk systematic ally related to any specific type of hormone drug treatment . Conclusions There was a small increase in the incidence of mental disorders in children born after ovulation induction/intrauterine insemination . Children born after in vitro fertilisation/intracytoplasmic sperm injection were found to have overall risk comparable with children conceived spontaneously
SUMMARY ANSWER The available high- quality evidence indicates that specific treatments may give rise to different effects on cognitive development , with certain treatments , including ICSI , associated with cognitive impairment .
STUDY QUESTION Does  fertility treatment  influence cognitive ability in school aged children , and does the impact vary with the type of treatment ?
WHAT IS KNOWN ALREADY Previous review s of the literature concerning cognitive outcomes among children conceived with medical assistance have concluded that study findings are generally ' reassuring ' , but limited attention has been paid to the quality of this research .
In addition , no review has separately assessed the range of treatment modalities available , which vary in invasiveness , and thus , potentially , in their effects on developmental outcomes .