Clinical outcome of pregnancies with the prenatal double bubble sign - a five-year experience from one single centre in mainland China.

The aim of this study was to describe the risk of aneuploidy, associated structural anomalies and clinical outcome in pregnancies with the prenatal double bubble sign. A retrospective study on ultrasound reports and pregnancy outcomes was performed in 71 foetuses with double bubble sign, who were examined at the Guangzhou Women and Children Medical Center during a five-year period. Forty-nine patients had the regular prenatal care since first trimester; of these, 20 had the sonographic sign before 24 weeks and the remaining 29 had the sonographic diagnosis after 24 weeks. Twenty-two patients presented beyond 24 weeks and the sonographic diagnosis was late. Fetal trisomy 21 was found in one of the 49 patients who had early and regular prenatal visits, but was confirmed in six out of the 22 patients who had late prenatal care. Only one out of the 49 cases had additional malformation. In the 22 subset cases, seven had additional malformations. Two pregnancies ended in intrauterine foetal demise and five patients opted for termination of pregnancy because of additional anomalies or abnormal karyotype. There were 63 live births. Postnatal verification revealed duodenal obstruction secondary to intrinsic or extrinsic cause in 60 cases; three cases excluded duodenal obstruction. The implementation of first trimester screening programme has significantly reduced the number of duodenal obstruction cases with trisomy 21 and associated malformations. Impact statement What is already known on this subject: The double bubble sign is strongly indicative of duodenal atresia. More than one-half of foetuses with duodenal atresia have associated anomalies, especially trisomy 21. What the results of this study add: The clinical outcome of foetuses with double bubble sign was first reported in mainland China. The implementation of first trimester screening programme has significantly reduced the number of duodenal atresia cases with trisomy 21 and associated malformations. What the implications are of these findings for clinical practice and/or further research: The early diagnosis of duodenal obstruction, as well as of other associated anomalies, will allow complementary investigation, immediate and proper care at birth and family counselling.