Developmental Medicine & Child Neurology



Original Articles

Characteristics of fetal anticonvulsant syndrome associated autistic disorder


AD Rasalam  a1 c1, Hailey  a2, JHG Williams  a1, SJ Moore  a3, PD Turnpenny  a4, DJ Lloyd  a5 and JCS Dean  a2
a1 Department of Child Health, University of Aberdeen, Aberdeen, Scotland, UK.
a2 Department of Medical Genetics, Aberdeen Royal Infirmary, Aberdeen, Scotland, UK.
a3 Medical Genetics Program, Memorial University of Newfoundland, St John's, Newfoundland, Canada.
a4 Clinical Genetics Service, Royal Devon and Exeter Hospital, Exeter, UK.
a5 Department of Neonatal Medicine, Royal Aberdeen Children's Hospital, UK.

Abstract

The aim of this study was to evaluate the clinical features and frequency of autistic disorder or Asperger syndrome (AS; according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition [DSM-IV] criteria) in children exposed to anticonvulsant medication in utero. During a 20-year study period, 626 children were born in Aberdeen to mothers taking antiepileptic drugs (AEDs). The study examined long-term effects of prenatal exposure to AEDs in 260 children (122 males, 138 females). Of these, 26 (16 males) were reported by parents to have social or behavioural difficulties. Eleven children (6 males, 5 females) fulfilled the DSM-IV criteria for autistic disorder and one (female) fulfilled the DSM-IV criteria for AS. These children comprised 4.6% of the exposed children studied, and 1.9% of all exposed children born during the study period. Mean age of these children at diagnosis was 5 years 4 months (SD 2y 11mo) and 9 years 10 months (SD 3y 10mo) at the time of this study. Other children from the group of 26 had difficulties in areas of speech and language development and social communication but did not meet the criteria for an autism spectrum disorder (ASD). Sodium valproate was the drug most commonly associated with autistic disorder, five of 56 (8.9%) of the study children exposed to sodium valproate alone had either autistic disorder or AS. It was concluded that prenatal exposure to anticonvulsant medication is a risk factor for the development of an ASD. Fetal anticonvulsant syndrome associated autistic disorder is characterized by an even sex ratio, absence of regression or skill loss, and language delay in the absence of global delay.

(Accepted August 6 2004)


Correspondence:
c1 Department of Child Health, University of Aberdeen, Royal Aberdeen Children's Hospital, Aberdeen AB25 2ZH, Scotland, UK. E-mail: adrasalam@nhs.net