ABSTRACT
Objective To analyze the ultrasonographic features of fetal palate in the second and third trimester. Methods Two-dimensional ultrasound was performed in 1 885 fetuses during 21 to 36 gestational weeks of pregnancy, including 1 023 cases in 2nd trimester and 862 cases in 3nd trimester. The normal fetal palate ultrasound images were conifrmed by postnatal examination. In the ultrasound examination, fetal palate coronary plane was scanned through submandibular region, oral ifssure and prootic region;longitudinal plane was scanned through oral ifssure. The detection rate of completely and continuously displayed fetal palate was calculated. Results In prenatal ultrasonography, the normal fetal hard palate was shown as a bright band and the normal soft palate as a hypoechoic band in coronary section through fetal submandibular region, oral ifssure and prootic region. The detection rate was 76%(777/1 023)in 2nd trimester group and 53%(458/862) in 3rd trimester group. The normal fetal palate was shown as continuous camber echogenic band in longitudinal plane through oral ifssure. The detection rate was 49%(501/1 023) in 2nd trimester group and 13%(113/862) in 3rd trimester group. The detection rate was 94%(961/1 023) in 2nd trimester group and 56%(483/862) in 3rd trimester group by the combination of two scanning approaches. Conclusions There is usually an obvious gap between mandible gristles in 2nd trimester fetus. Fetal palate is accessible regardless of fetal head position by coronary scanning through submandibular region, oral ifssure and prootic region and longitudinal scanning through oral ifssure. These planes could display fetal palate well, and might be useful in detecting isolated secondary cleft palate. But these scanning approaches and planes might not suitable for routine screening due to operator dependence.