Detection rates of a national fetal anomaly screening programme: A national cohort study.

ABSTRACT

OBJECTIVE: To measure condition-specific detection rates for 14 physical conditions screened for by the NHS fetal anomaly screening programme (FASP) fetal anomaly (FA) ultrasound scan. DESIGN: Retrospective audit of 12 694 diagnoses across a 3-year national cohort. SETTING: All English NHS and crown-dependency hospital trusts providing maternity services. POPULATION Pregnancies booked for maternity services with an expected date of delivery between 1 April 2017 and 31 March 2020 and at least one diagnosis of a condition screened for by FASP. METHODS: Active multi-source ascertainment, linkage, audit and validation of clinical information to identify the subset of diagnoses meeting the condition-specific positivity threshold for the FA scan. MAIN OUTCOME MEASURE: The accuracy of the FA scan compared with diagnostic reference standards. RESULTS: FA scan detection rates were anencephaly 96.3% (95% confidence interval [CI] 81.7-99.3%), atrioventricular septal defect 69.2% (95% CI 65.8-72.4%), bilateral renal agenesis 98.7% (95% CI 95.4-99.6%), cleft lip 89.5% (95% CI 87.8-90.9%), congenital diaphragmatic hernia 60.8% (95% CI 56.5-65%), Edwards syndrome 73.8% (95% CI 67.5-79.3%), exomphalos 59.4% (95% CI 49.4-68.7%), gastroschisis 88.6% (95% CI 79-94.1%), hypoplastic left heart syndrome 92.7% (95% CI 90-94.8%), lethal skeletal dysplasia 93.2% (95% CI 88.6-96%), Patau syndrome 82.3% (95% CI 72.4-89.1%), spina bifida 93.8% (95% CI 91.8-95.3%), tetralogy of Fallot 75.4% (95% CI 72.1-78.4%) and transposition of the great arteries 84.9% (95% CI 81.7-87.5%). CONCLUSIONS: The performance of the FA scan is above the expectations set in 2010 for most conditions. For the remaining conditions, the majority of fetuses and babies affected are detected before the FA scan.