To explore the value of prenatal ultrasound diagnosis of fetal body stalk anomaly (BSA) in first trimester.

Seventeen cases with body stalk anomaly diagnosed in first trimester at Department of Ultrasound Diagnosis in Hubei Maternal and Child Health Hospital from 2009 to July 2014 were included in the study. The prenatal sonographic characteristics were analyzed from the seventeen cases with BSA in first trimester, fifteen of whom were compared with the pathological autopsy results.

The ultrasonographic features of BSA in first trimester were the same as the findings in second and third trimesters, including major abdominal wall defect and mass, severe kyphoscoliosis, limb abnormalities, craniofacial defects, neural tube defects, and short umbilical cord. Some of them (10 cases) were associated with other malformations, such as cardiac anomalies, urinary tract anomalies and so on. There are several characteristic ultrasound features for BSA in first trimester, including under-gestational age crown rump length (CRL), increased nuchal translucency (NT), persisted extra-embryonic celomic cavity, and mass outside amniotic cavity. All of seventeen cases choose to terminate pregnancy. Of them, fifteen cases were confirmed by gross pathology. Three cases were type I, which were characterized by the craniofacial defects. Twelve cases were typeⅡ, which were characterized by abdominal placental attachment. Eight cases were associated with limbs defect. Nine cases with fetal heart and lime abnormalities were missed or misdiagnosed.

System ultrasonography screening in first trimester has important clinical value in diagnosing BSA. It is prone to missed diagnosis and misdiagnosis for BSA with abnormalities of fetal heart and limbs in first trimester.