To investigate the clinical value of abnormal course of fetal superior mesenteric arteries (SMA) detected by ultrasound during the first trimester (11-13⁺⁶ weeks) in predicting congenital diaphragmatic hernia (CDH).

This study enrolled women who underwent fetal nuchal translucency (NT) screening during the first trimester in Central Hospital of Panyu District from March to December 2017. Low-speed high-definition flow imaging was used to observe the course of fetal SMA, and it was regarded as abnormal when the angle between SMA and abdominal aorta >90°. Once abnormal course of the SMA was suspected, the position of fetal thoracic cavity and abdominal organs would be scanned carefully. Furthermore, ultrasound examinations would be repeated at 16-18, 20-24, 28-32 and 37-40 weeks of gestation. Fetus diagnosed as CDH by ultrasound would be scheduled for MRI or autopsy to confirm the diagnosis. Pregnancy outcomes of all cases were followed up by telephone. Descriptive statistical analysis was used in this study.

A total of 6 899 gravidas (6 964 fetuses) underwent NT scan during the first trimester were enrolled and the SMA of all fetuses were successfully displayed. Three cases with abnormal course of the SMA were identified. Two of them were diagnosed with left CDH at 17⁺ and 23⁺ weeks of gestation, which was confirmed by autopsy after termination of pregnancy, and the other one terminated pregnancy in first trimester due to a large omphalocele. Among the 6 961 fetuses with normal SMA, the pregnancy outcomes of 6 120 were successfully followed up, only one of which was found to have left CDH at 32 gestational weeks by ultrasound examination, and was later confirmed by neonatal MRI after delivery. No other fetal CDH was detected.

Abnormal course of the SMA identified in early pregnancy may be a simple and effective indicator for CDH that allow early intervention and treatment.

Pregnancy trimester, first; Mesenteric artery, superior; Congenital abnormalities; Hernias, diaphragmatic, congenital; Forecasting