Abstract:

Objective　To investigate and compare two-dimentional and multiplanar sonograms of fetal retronasal triangles during the first trimester of pregnancy.　Methods　Sonographic data from 89 healthy pregnant women at the time of first-trimester period were collected. The mid-sagittal, coronal, transverse and multiplanar views of fetal retronasal triangle were evaluated and analyzed.　Results　Both 2D and TUI views showed the retronasal triangle clearly. The fetal nasal bone and palate showed clearly on the mid-sagittal views, retronasal triangle composed with processus frontalis maxillae and palate showed on coronal views, the relationship of retronasal triangle and palate showed clearly on the transverse views. The qualified rate and scores in the mid-sagittal and coronal views showed no difference between 2D and TUI views (P>0.05), but  was more better on TUI than 2D, for transverse views (P<0.05).　Conclusions　Both 2D and TUI could determine the retronasal triangle during the first trimester of pregnancy. The sonographic examination of retronasal triangle may be useful in the early diagnosis of cleft palate.

Key words: Fetus, First trimester, Retronasal triangle, Tomographic, Ultrasound