Risk of autism spectrum disorders in children born after assisted conception: a population-based follow-up study
- 1Institute of Public Health at the Department of Epidemiology, University of Aarhus, Aarhus, Denmark
- 2Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities, Atlanta, Georgia, USA
- 3Fertility Section, Department of Obstetrics and Gynaecology, Aarhus University Hospital, Aarhus, Denmark
- Correspondence to Dr Dorte Hvidtjørn, Institute of Public Health, at the Department of Epidemiology, University of Aarhus, Paludan-Müllers Vej 17, 8000 Aarhus C, Denmark; dh{at}soci.au.dk
-
Contributors DH, PT and JG were responsible for conception and design. DH, JG and CS conducted the statistical analyses and the interpretation of data. DH wrote the first draft of the manuscript. All authors provided critical input at all stages and critically reviewed and contributed to the final draft. PT and DH are guarantors of the study. All authors had full access to the data.
- Accepted 30 December 2009
- Published Online First 27 June 2010
Abstract
Objectives To assess the risk of autism spectrum disorders (ASD) in children born after assisted conception compared with children born after natural conception.
Design Population-based follow-up study.
Setting All children born alive in Denmark 1995–2003.
Participants 588 967 children born in Denmark from January 1995 to December 2003. Assisted conception was defined as in vitro fertilisation (IVF) with or without intracytoplasmic sperm injection and ovulation induction (OI) with or without subsequent insemination. Children exposed to IVF or OI were identified in the IVF Register and in the Danish Drug Prescription Register.
Main outcome measures A diagnosis of ASD in the Danish Psychiatric Central Register.
Results 33 139 (5.6%) of all children born in Denmark in 1995–2003 resulted from assisted conception, 225 of whom (0.68%) had a diagnosis of ASD. Of the 555 828 children born in this period after natural conception, 3394 (0.61%) had a diagnosis of ASD. The follow-up time was 4–13 years (median 9 years). In crude analyses, children born after assisted conception had an increased risk of a diagnosis of ASD: crude hazard rate ratio (HRR) 1.25 (95% CI 1.09 to 1.43). In analyses adjusting for maternal age, educational level, parity, smoking, birth weight and multiplicity, the risk disappeared: adjusted HRR 1.13. (95% CI 0.97 to 1.31). However, subgroup analyses that suggest possible associations in women who received follicle stimulating hormone indicate the need for further study.
Discussion This population-based follow-up study found no risk of ASD in children born after assisted conception.
Footnotes
-
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.
-
Funding The study was funded as a co-financed PhD project by The Danish Agency for Science, Technology and Innovation, University of Aarhus and The Elsass Foundation. Further funding was supplied by Sofiefonden, The Health Insurance Foundation, The Augustinus Foundation, Julie von Müllens Foundation, Direktør Jacob Madsen and Hustru Olga Madsens Fond and Aase and Ejnar Danielsen Foundation.
-
Competing interests None.
-
Ethics approval Approval for this study was obtained from the Danish Data Protection Agency.
-
Provenance and peer review Not commissioned; externally peer reviewed.
