Accuracy of prenatal detection of facial clefts and relation between facial clefts, additional malformations and chromosomal abnormalities: a large referral-center cohort.

Purpose: Facial clefts belong to the most common congenital malformations and their prenatal diagnosis is a constant challenge. The aim of this study was to determine the accuracy of prenatal ultrasound in correctly classifying facial clefts. Furthermore, we aimed to specify the distribution of the type of clefts and underlying genetic conditions.

Methods: All fetuses seen with suspected facial cleft in the Department of Obstetrics, Charité - Universitätsmedizin Berlin during a period of 23 years (1999-2022) were included in this retrospective study. Clefts were classified according to the classification of Nyberg. All additional prenatal findings were assessed and correlated with the outcome. The accuracy of prenatal diagnosis was assessed.

Results: 292 patients were included in the study. The most common type of clefts were unilateral cleft lip and palate (CL-P) (53.6%) and bilateral CL-P (30.6%), followed by CL (8.1%), CP (5.1%) and median CL-P (2.6%). The overall pre- and postnatal concordance rate corresponding to a correct prenatal diagnosis was high, 88.9%, ranging from 73.7% (CL) to 93.7% (unilateral CL-P). Most of the median clefts (95.2%) and CP (93.3%) were associated with other sonographic abnormalities, as well as 52.2% of bilateral CL-P. Chromosomal abnormalities, mostly trisomy 13 and trisomy 18, were observed in in the median CL-P (47.6%), bilateral CL-P (31.1%) and CP (26.7%) groups, in contrast to the CL (9.1%) and unilateral CL-P (12.9%) groups. It was exceptional to have a chromosomal abnormality without additional malformations (4.8%). The mortality rate including one late miscarriage, 5 IUFD's, 74 TOPs and 6 palliative cares at birth was 29.8%, particularly high for median clefts (90.5%).

Conclusion: Prenatal ultrasound exhibited a high accuracy to assess the type of facial clefts with an average rate of 88.9% (73.7%-93.7%) and a concordance rate of up to 93.7%, depending on the type of cleft. The search for additional malformations as well as clarifying underlying genetic conditions is essential. This allows for a targeted counseling of the parents and to best prepare for postnatal care, including surgery by the maxillofacial team.