Evaluation of prenatal and postnatal ultrasonography for the diagnosis of fetal double bubble sign.

Background: Congenital duodenal obstruction (CDO) is commonly detected antenatally through the presence of the "double bubble" sign on prenatal ultrasound, denoting dilatation of the stomach and duodenum. Subsequent postnatal ultrasonography plays a pivotal role in determining the causes of obstruction, thereby informing surgical strategies and neonatal management. The aim of this study was to investigate the diagnostic accuracy of postnatal ultrasonography in comparison to that of prenatal ultrasound and surgical findings in a cohort of 43 patients with fetal double bubble sign.

Methods: A total of 43 patients, comprising 24 males and 19 females, who exhibited double bubble sign on prenatal ultrasound were subjected to postnatal ultrasound assessment at a tertiary care facility during the 2018-2023 period. The accuracy of both pre-and postnatal ultrasonography in the identification and diagnosis of CDO, as well as its underlying causes, was compared to that of the established gold standard of surgical findings.

Results: The accuracy rates for prenatal and postnatal ultrasonic diagnosis of CDO were 97.7% (42/43) and 100% (42/42), respectively. In terms of etiological diagnosis, prenatal and postnatal ultrasound correctly identified the causes of obstruction in 45.2% (19/42) and 81.0% (34/42) of cases, respectively, as confirmed by surgical intervention.

Conclusions: The presence of the prenatal double bubble sign serves as a highly reliable indicator for CDO. Additionally, postnatal ultrasonography proved to be a valuable tool in refining the diagnosis and determining the underlying causes of obstruction in neonates.