Absence of the stomach on prenatal ultrasound is most consistent with which anomaly?

• A. Esophageal atresia
• B. Duodenal atresia
• C. Meconium peritonitis
• D. Hyperechoic bowel

Answer: (A)

Swallowing amniotic fluid fills the stomach, so a visible gastric bubble is usually seen on prenatal ultrasound. When the stomach is absent, it points to a blockage proximal to the stomach, most commonly esophageal atresia (with or without a tracheoesophageal fistula). The esophagus fails to form a continuous passage, so swallowed fluid cannot reach the stomach, leading to an absent gastric bubble and often polyhydramnios due to impaired fetal swallowing.

In contrast, a blockage downstream of the stomach, such as in duodenal atresia, typically still shows a stomach bubble and presents with a double bubble sign from dilation of the stomach and proximal duodenum. Meconium peritonitis would show intraperitoneal calcifications and related signs rather than an absent stomach bubble. Hyperechoic bowel reflects bowel pathology, not the gastric bubble status.