OBJECTIVE To determine the incidence of fetal alcohol syndrome (FAS) in the UK in children aged 0-16 years.

DESIGN Active surveillance was undertaken through the British Paediatric Surveillance Unit between October 2018 and October 2019 inclusive. Data were collected from reporting clinicians using standardised questionnaires.

PATIENTS Children aged 0-16 years in the UK and Ireland with a diagnosis of FAS seen in the previous month. This study did not include children with fetal alcohol spectrum disorder.

MAIN OUTCOME MEASURES Demographic details (including age and ethnicity), details of exposure, growth parameters, neurological and cognitive diagnoses, and service usage.

RESULTS 148 notifications were received. After exclusions and withdrawals, there were 10 confirmed and 37 probable cases (analysed together). Just 24 of these children were newly diagnosed with FAS during the surveillance period, giving an estimated incidence rate of 3.4/100 000 live births (95% CI 2.2 to 5.0); their median age at diagnosis was just over 5 years and they were diagnosed between 3 months and 14 years 3 months of age.

CONCLUSIONS The estimated incidence rate of FAS is lower than reported by similar studies and there was a wide variation in the age that cases were diagnosed. This, combined with the fact that many cases were notified and then withdrawn or excluded, suggests that in the UK there is a lack of consistency and certainty in diagnosing FAS. The study findings strongly support the need to educate key professionals involved in the care of infants and children at risk of FAS.