Prenatal double bubble with distal fluid: Not a marker for malrotation with volvulus

BackgroundThe prenatal "double bubble" (DB) sign is a marker of duodenal obstruction. When accompanied by distal bowel fluid on prenatal imaging, concern may arise for malrotation with volvulus. This study evaluated whether distal bowel fluid in fetuses with a prenatal DB sign is associated with malrotation or volvulus.MethodsWe performed an 11-year retrospective review (Jan 2015-Dec 2025) of fetuses with a prenatal DB sign evaluated at a single tertiary care center. Prenatal ultrasound and fetal MRI findings, operative diagnoses, and neonatal outcomes were reviewed, with specific attention to distal bowel fluid on fetal MRI.ResultsTwenty-nine fetuses were identified. Median gestational age at birth was 37.5 weeks (IQR 34.5-38.0), and polyhydramnios was present in 62.1%. Fetal MRI was performed in 10 cases, demonstrating distal bowel fluid in 5. No prenatal imaging suggested volvulus. Among 27 neonates undergoing surgery, duodenal obstruction was confirmed in 25 (93.8%). Asymptomatic malrotation was identified in 5 infants, and no cases of prenatal or postnatal midgut volvulus occurred. One-year survival was 100%.ConclusionsPrenatal DB is a highly sensitive marker of duodenal obstruction. Distal bowel fluid on fetal MRI was not associated with malrotation with volvulus, supporting reassurance during prenatal counseling.