Fetal esophageal imaging: Early pregnancy as a window of opportunity

Objective To describe the sonographic appearance of the fetal esophagus during early pregnancy and evaluate the feasibility of imaging the entire esophageal length. In addition, we present a case of disrupted esophageal continuity, subsequently diagnosed with esophageal atresia (EA). Methods A prospective observational study of 145 patients. During the early second trimester anomaly scan performed at 12–17 weeks' gestation the entire esophagus was captured in a single sonographic image at the midsagittal plane (one shot technique). Postnatal follow‐up of esophageal patency included review of medical records and telephone interviews. Results Complete visualization of the esophagus (neck to diaphragm) was possible in 144 cases. In 88% of cases the esophagus was demonstrated by transvaginal approach. The time required to obtain the desired view of the esophagus, once the fetus was in an optimal position, was on average 13 s (range: 5–30 s). In one case at 15 weeks' gestation, the cervical segment of the esophagus was demonstrated while the lower thoracic segment was not identified. Subsequently EA was diagnosed. Conclusions It is feasible to demonstrate the entire esophagus during early second trimester anomaly scan. An early second trimester anomaly scan may serve as a window of opportunity for EA screening. Key Points What's already known about this topic? The prenatal diagnosis of esophageal atresia (EA) is challenging. Currently, EA has a low prenatal detection rate ranging from 24% to 32%. Prenatal signs suggestive of EA are polyhydramnios and/or small or absent stomach. The pouch sign is the only prenatal diagnostic sign of EA, however, its detection requires significant expertise. A recent publication found that the early anomaly scan, in its current form, performs poorly in screening for EA. What does this study add? We present a new “one shot” technique for assessing the fetal esophagus at early pregnancy and evaluate its feasibility. Furthermore, we were able to consistently apply this technique in a prospective cohort. The major clinical implication of this work is to present a promising early screening method for EA.