To explore the characteristics of prenatal ultrasonography characteristics of fetal hemivertebra to assess the clinical value of prenatal ultrasonography in this congenital spinal abnormality.

Fetal ultrasound images for fetuses who underwent prenatal ultrasound structural screening at Suzhou Hospital Affiliated to Nanjing Medical University from January 2015 to December 2019 were selected. Ultrasonographic features and associated malformations of fetal hemivertebra were analyzed. All fetuses were followed to birth or induction of labor. The value of prenatal ultrasound in the diagnosis of fetal hemivertebral body was then assessed.

A total of 100 822 fetuses were included in the study. Among them, 97 cases of hemivertebra were diagnosed by prenatal ultrasound, including 67 cases of single hemivertebra and 30 cases of multiple hemivertebra. The most common associated malformations were vascular anomalies (17 cases), central nervous system anomalies (16 cases), urinary anomalies (16 cases), and cardiac anomalies (15 cases). During follow-up, 7 cases were lost. Of the remaining 90 cases of hemivertebra, 84 were confirmed by fetal magnetic resonance imaging (MRI), X-ray examination after birth, or induction of labor, 4 were finally diagnosed as butterfly vertebrae, and 2 were normal. Out of 98 562 fetuses without abnormal ultrasound findings who were followed, 2958 were lost to follow-up, 95 595 were normal after birth, and 9 were misdiagnosed by prenatal ultrasound, which were confirmed after birth. The diagnostic accuracy of prenatal ultrasound for hemivertebra was 93.33% (84/90), and the sensitivity, specificity, positive predictive value, and negative predictive value were 90.32% (84/93), 99.99% (95 595/95 597), 97.67% (84/86), and 99.99% (95 595/95 604), respectively.

Hemivertebra has typical ultrasonographic characteristics. Prenatal ultrasound is the main approach to diagnose fetal hemivertebra, with a high sensitivity and specificity, which is conducive to evaluation of the type and location of lesions, early diagnosis, evaluation of fetal prognosis, and clinical management.