Fetal hemivertebra: associations and perinatal outcome.

Objectives: To assess the accuracy of antenatal diagnosis of hemivertebra, to quantify the association with coexisting anomalies and to determine the perinatal outcome.

Method: This was a retrospective observational study of all cases of suspected fetal or neonatal hemivertebra identified via the UK Southwest Congenital Anomaly Register (SWCAR) between 2002 and 2012.

Results: From a total of 88 cases of hemivertebra identified during the study period, data were obtained for 67 of them: 45 (10 isolated and 35 with coexisting anomalies) cases were suspected antenatally and 22 (10 isolated and 12 with coexisting anomalies) were diagnosed postnatally. Of the cases detected postnatally, five (four with coexisting anomalies) were unsuspected and diagnosed at postmortem examination. The most commonly associated anomalies included additional skeletal abnormalities (n = 16), genitourinary abnormalities (n = 10), VATER/VACTERL association (n = 5), cardiac abnormalities (n = 4) and central nervous system abnormalities (n = 4). In cases with coexisting anomalies there was a 48% fetal/neonatal loss, compared to 19% in cases with isolated hemivertebra.

Conclusions: Although antenatal diagnosis of hemivertebra was accurate, a third of the cases were diagnosed only postnatally. These data suggest a difficulty in antenatal diagnosis of the condition. The majority of cases of hemivertebra had coexisting anomalies, and in these cases the rate of perinatal loss was high. These data should be useful in providing additional information for counseling when a diagnosis of hemivertebra is made.