Objective
To investigate the overall and type-specific prenatal detection rates (DRs) of orofacial clefts in a national cohort in Denmark.

Methods
This study was based on data from the Danish Fetal Medicine Database and included all fetuses and children from singleton pregnancies diagnosed with an orofacial cleft prenatally and/or postnatally between 2009 and 2018. The types of cleft included unilateral, bilateral or median cleft lip (CL); unilateral, bilateral or median cleft lip with secondary cleft palate (CLP); and cleft palate (CP). The clefts were grouped as cleft lip with or without cleft palate (CL(P)) or as all clefts (including CP). All cases with discordance between prenatal and postnatal diagnoses were validated in the local patient files (Astraia). Cases without prenatal validation of the postnatal diagnosis were marked as undetected. Postnatally diagnosed cases with a strong prenatal suspicion of a cleft but without an International Classification of Diseases-10 code were registered as prenatally detected. Termination of pregnancy and intrauterine death were registered as true positives even if no autopsy could be performed. Liveborn cases with a prenatal diagnosis but without a postnatal validation were excluded.

Results
A total of 994 cases were included in the study, of which 933 were liveborn. The prevalence of orofacial cleft was 1.6 per 1000 live births. There were no differences in the baseline characteristics between detected and undetected cases. The DR for CL(P) was 71.7% (95% CI, 64.8–78.9%), with an increase from 60.0% in 2009 to 73.0% in 2018 (P = 0.018). The type-specific DRs for the entire period were 56.4% (95% CI, 45.0–67.6%) for unilateral CL; 76.6% (95% CI, 71.7–82.9%) for unilateral CLP; 70.5% (95% CI, 52.1–87.6%) for bilateral CL; 82.3% (95% CI, 70.6–93.6%) for bilateral CLP; 0% (0/6) for median CL; 75.0% (3/4) for median CLP; and 3.3% (95% CI, 0.6–5.7%) for CP. A total of 20.9% (208/994) of the cases had associated findings, of which 33.2% (69/208) were genetic aberrations.

Conclusions
The DR for CL(P) has improved in Denmark over the last decade. The DR for CLP is high, with the highest DR for bilateral CLP. However, prenatal detection of CP remains a challenge. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.