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 Prospective 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 systematically 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.
In this large long term follow-up of an unselected cohort of children conceived after fertility treatment, we found a systematically small increased risk of mental disorders in children born after induced ovulation/intrauterine insemination compared with spontaneously conceived children. When we considered the diagnoses in categories of mental disorders, there was a significant increased risk of autistic spectrum disorders, hyperkinetic disorders, tic disorders, and conduct, emotional, or social disorders. In contrast, beside a borderline significantly increased risk of tic disorders, we found no association between conception after IVF/ICSI and risk of mental disorders in childhood or adolescence. There were no systematic associations between cryopreserved embryos or gametes, types of hormones, or cause of infertility and risk of mental disorders.
What is known on this topic
- Children born after fertility treatment have an increased risk of some perinatal outcomes such as low birth weight, shorter gestational age, and congenital malformations
- The risk of malformations is related to the subfertility rather than the procedures or treatments
- Long term development is sparsely investigated and few have studied children born after induced ovulation
- The overall long term development of children born after IVF/ICSI is comparable with that of children conceived spontaneously
- Children born after induced ovulation seem to have a small increased risk of autism, hyperkinetic disorders, conduct, emotional or social disorder, and tic disorders, but the absolute risks are low
- Source: BMJ
What this study adds