Barcelona FGR Staging (Figueras & Gratacos)

The Barcelona classification (Figueras & Gratacos, Fetal Diagn Ther 2014) is a staged, Doppler-based protocol for distinguishing constitutionally small-for-gestational-age (SGA) fetuses from true fetal growth restriction (FGR) and for sequencing surveillance and delivery timing in FGR by severity. A fetus with estimated fetal weight (EFW) or abdominal circumference between the 3rd and 10th percentile with entirely normal Doppler indices (uterine artery PI, umbilical artery PI, and cerebroplacental ratio all normal) is classified as SGA rather than FGR, and is managed less intensively. True FGR is staged I through IV by the most severe Doppler or biophysical abnormality present: Stage I is EFW below the 3rd percentile with otherwise normal Doppler, or EFW below the 10th percentile plus an abnormal uterine artery PI, umbilical artery PI, or cerebroplacental ratio (each above/below their 95th/5th percentile respectively); Stage II is umbilical artery absent end-diastolic flow; Stage III is umbilical artery reversed end-diastolic flow or a ductus venosus PI above the 95th percentile; Stage IV is an absent or reversed ductus venosus a-wave, or an abnormal cardiotocogram (reduced short-term variation, spontaneous decelerations), signifying imminent fetal deterioration. Each stage carries a progressively shorter recommended surveillance interval and an earlier delivery threshold, reflecting the rising risk of stillbirth and acidemia at more advanced stages. The classification presumes gestational-age-appropriate percentile references have already been applied to each measurement.