Congenital absence of salivary glands in fetuses with trisomy 21

Background: The congenital absence of salivary glands has been reported in children but never in fetuses with trisomy 21. Objectives: To determine whether the congenital absence of salivary glands can be detected prenatally between 13 and 16 weeks of gestation in normal and trisomy 21 fetuses using transvaginal ultrasound. Methods: We performed a retrospective analysis of recordings of normal and trisomy 21 fetuses. Inclusion criteria were a single viable fetus and good visualization of the anatomic area of the salivary glands on both sides of the fetal face. All videos were reviewed by one examiner who reported the presence or absence of one or more salivary glands and was blinded to the fetal karyotype. Results: Of the 45 videos reviewed, 4 were excluded from the study: namely, a non-viable fetus, a twin pregnancy, and in 2 there was unsatisfactory visualization of the anatomic area of the salivary glands. Of the remaining 41 fetuses, 24 had trisomy 21 and 17 were normal. In the trisomy 21 fetuses, 8 (33.3%) had congenital absence of one or more salivary glands compared to 1 of 17 normal fetuses (5.9%) (P < 0.05). Conclusions: Congenital absence of the salivary glands has a high specificity but low sensitivity for detecting trisomy 21 fetuses.