Objective: The current study evaluates the diagnostic value of screening for a fetal cleft palate by using the ultrasound-based observation of the "superimposed-line" sign appearing at the junction of the vomer and maxilla in the first trimester of pregnancy. Methods: Retrospective analyses were performed of ultrasonographic images of nuchal translucency (NT) obtained during the first trimester of pregnancy (11–13+6 weeks) from 45 fetuses with a cleft palate later confirmed following parturition or induced labor (cases) and 4500 normal fetuses confirmed after parturition (controls). Ultrasonographic features of the "superimposed-line" sign were observed and recorded

and between-group comparisons were performed. Results: The "superimposed-line" sign was absent in 39 cases (86.67%)

including 4 (8.89%) with simple secondary hard palate cleft and 35 (77.78%) with secondary hard palate cleft complicated by a primary cleft palate. 6 cases showed the "superimposed-line" sign (13.33%)

including 2 (4.44%) with a simple secondary soft palate cleft

1 (2.22%) with a simple secondary bifid uvula

and 3 (6.67%) with a simple primary cleft palate. Among the 4500 controls

4469 fetuses showed the "superimposed-line" sign (99.31%) and 31 fetuses showed an absence of the "superimposed-line" sign (0.69%). The between-group difference was significant (p<0.05). The sensitivity

specificity

positive predictive value

and negative predictive values of the "superimposed-line" sign in the first trimester of pregnancy for predicting fetal cleft palate were 86.67%(39/45)

99.31%(4469/4500)

55.71%(39/70)

and 99.86%(4469/4475)

respectively. Conclusion: The "superimposed-line" sign did not appear in fetuses with secondary hard palate cleft and primary cleft palate only when a secondary hard palate cleft is present. The sign appeared in normal fetuses and those with a simple primary cleft palate

simple secondary soft palate cleft

or with a simple secondary bifid uvula. Based on these results

we propose that the "superimposed-line" sign in the mid-sagittal plane of the fetal face in the first trimester of pregnancy is an important tool in screening for fetal cleft palate

especially secondary hard palate cleft.