Prenatal Ultrasound Diagnosis of Fetal Intestinal Volvulus Without Malrotation: A Series of Seven Cases and Literature Review

Background: To elucidate the prenatal ultrasonographic characteristics and clinical prognosis of fetal intestinal volvulus in the absence of malrotation, a rare and potentially life-threatening condition. Methods: A retrospective analysis was conducted on seven cases of fetal intestinal volvulus diagnosed prenatally using ultrasound at the Women and Children’s Hospital, School of Medicine, Xiamen University, between July 2021 and December 2024. Ultrasonographic findings, including the whirlpool and vascular spiral signs, were correlated with postnatal surgical or autopsy outcomes, operative reports, intraoperative findings, postoperative pathology, and clinical recovery data. Results: Maternal age ranged from 24 to 34 years, with initial diagnoses made at 23–33 weeks of gestation. All seven cases exhibited whirlpool and vascular spiral signs, with additional findings including bowel dilation (7/7), ascites (6/7), abdominal pseudocysts (2/7), and coffee bean sign (2/7). A total of 27 ultrasound examinations were performed, with whirlpool and vascular spiral signs detected in 20 of the 27 examinations. Six fetuses were born alive (five preterm) and underwent neonatal surgery, confirming volvulus with necrosis and intestinal atresia (four type III) in five cases. One pregnancy was terminated because of parental concerns about severe complications, with an autopsy confirming volvulus and necrosis. Conclusions: Fetal intestinal volvulus exhibits distinct ultrasonographic features, including whirlpool and vascular spiral signs, which enable early and precise prenatal diagnosis. This provides a critical foundation for timely intervention decisions and improved perinatal outcomes. Prenatal ultrasound is instrumental in identifying volvulus early, facilitating multidisciplinary perinatal collaboration, optimizing prenatal counseling, and enhancing fetal outcomes through timely postnatal management.