Abstract
Introduction
Developments in the use of ultrasound during pregnancy for assessment of fetal spine abnormalities indicate a need for accurate information about the antenatal development of the vertebral column. The published work is deficient in this regard, with available data examining only the period of 8–26 weeks. The aims of this study are to establish antenatal spine growth curves with fetal radiographs, to establish growth velocity curves for each anatomical spinal, region and to calculate the multiplier factor during antenatal life.
Methods
75 anteroposterior spine radiographs were retrieved from the fetal pathology unit. Cases with spinal anomalies were excluded from analysis. Individual vertebral regions were measured from radiographs with the method of Bagnall and colleagues,1 with use of DICOM software. Polynomial regression analysis was applied to each measurement with PASW statistics 18 (SPSS, Chicago, IL, USA).
Results
47 cases were included in the analysis. Gestational age ranged from 14–40 weeks. Growth velocity was greatest in the thoracic region and least in the sacral region. The table shows regression equations for each spinal region.
Conclusions
Regression equations from this study will have direct clinical application in the antenatal ultrasound assessment of fetal maturity and normality, particularly the third trimester data. Use of the standard error of the estimate as an approximation to normal values will allow antenatal identification of anomalies, particularly in cases of scoliosis, spina bifida, and anencephaly.