Comparison of two-dimensional and three-dimensional sonography in evaluating fetal malformations.

PURPOSE

We assessed the differences between 2-dimensional (2D) and 3-dimensional (3D) sonography (US) in evaluating fetal malformations.

METHODS

Both 2D US and 3D US were used to examine pregnant women whose fetuses had malformations. The diagnostic information provided by the modalities was evaluated and compared.

RESULTS

A total of 62 malformations were confirmed by postnatal or postmortem follow-up in 41 fetuses of 40 pregnant women. 2D US made a definite and correct diagnosis of 49 malformations (79%), whereas 3D US definitely diagnosed 58 malformations (94%) (p < 0.01). 3D US definitely diagnosed all the abnormalities in 38 fetuses (93%), whereas 2D US did so in only 32 fetuses (78%) (p < 0.05). In 35 (60%) of the 58 malformations revealed by both 3D US and 2D US, the former provided more diagnostic information than the latter. 3D US was particularly superior to 2D US in evaluating fetal malformations of the cranium and face, spine and extremities, and body surface.

CONCLUSIONS

In comparison with 2D US, 3D US improves the diagnostic capability by offering more diagnostic information in evaluating fetal malformations, particularly in displaying fetal malformations of the cranium and face, spine and extremities, and body surface. 3D US is a valuable adjunct to 2D US in prenatal diagnosis.