Objective: To review pregnancy outcomes when two or more ultrasound scans persistently fail to visualize the fetal stomach. Methods: A computerized ultrasound database was used to identify all fetuses in which two or more serial ultrasound examinations failed to visualize the fetal stomach. Sonographic images were reviewed retrospectively, with the reviewer blinded to outcome data, to confirm persistent nonvisualization. Pregnancy outcome data were obtained from hospital charts and physicians' office records. Fetal karyotypes, when performed, were obtained from amniotic fluid (AF) culture. The ultrasound findings then were compared with fetal karyotype results and pregnancy outcome data. Results: Of 35,569 ultrasound scans performed during 1991-1996, 26 fetuses (0.07%) with persistently nonvisualized stomachs were identified. Structural defects were detected in 17 fetuses (65%), most often involving the cardiothoracic (n = 5), genitourinary (n = 4), and central nervous systems (n = 4). Karyotypes were obtained in 12 fetuses, and four of them were abnormal. Only five of 17 fetuses (29%) with a structural defect survived. In nine of 26 fetuses (35%) with persistently nonvisualized stomachs, no structural defect was identified. Each of these nine fetuses had abnormal AF volume in its surrounding sac, and the overall perinatal survival in fetuses without a structural defect was only 50%. Conclusion: Fetuses with persistently nonvisualized stomachs have an increased incidence of structural defects and AF abnormalities and are more likely to have a poor outcome. A detailed ultrasound examination and fetal karyotype analysis should be performed to evaluate fetuses with persistently nonvisualized stomachs.