First-trimester diagnosis of cleft lip and palate using three-dimensional ultrasound.

OBJECTIVE

To determine whether systematic examination of primary and secondary palates using three-dimensional (3D) ultrasound aids in the identification of orofacial clefts in the first trimester.

METHODS

3D datasets were acquired prospectively from women undergoing first-trimester ultrasound screening for aneuploidy. Multiplanar mode display was used for offline analysis of (1) the primary palate in the coronal plane at the base of the retronasal triangle and (2) the secondary palate by virtual navigation in the axial plane. In addition, 3D datasets from three fetuses with a cleft palate diagnosed in the first trimester were retrospectively identified and included randomly in the study group.

RESULTS

A total of 240 3D datasets from 237 pregnancies (including three sets of twins), 89% of which were obtained transabdominally and 11% transvaginally, were examined independently by three operators. The quality of the 3D datasets was classified subjectively as good, fair and poor in 76%, 20% and 4% of cases, respectively. Seven fetuses had an orofacial cleft; all involved both the primary palate and the secondary palate. Using 3D offline analysis, the primary palate was classified as intact in 229 (95%), cleft in nine (4%) and indeterminate in two (1%). Seven of the nine fetuses suspected to have a cleft affecting the primary palate had the cleft confirmed at birth or at postmortem examination (false-positive rate 0.9% (2/231)). The secondary palate was classified as intact in 217 (90%), cleft in six (3%) and indeterminate in 17 (7%). Clefts of the secondary palate were confirmed in all six suspected cases and missed in one, which was diagnosed at 16 weeks. The visualization rate was affected by the quality of the 3D dataset (P < 0.001) and gestational age at evaluation (P < 0.01).

CONCLUSION

In our series, all cases of clefting of the primary palate and 86% of cases involving the secondary palate were visualized using 3D ultrasound with a satisfactory false-positive rate. Virtual navigation of the fetal palate using the multiplanar mode display seems to be useful in the diagnosis of clefting in the first trimester.