Decrease in Prevalence of Cleft lip, Alveolus and Palate After Nationwide Introduction of the Second-Trimester Anomaly Scan in the Netherlands

Some studies have suggested that introducing a second-trimester anomaly scan (SAS) leads to increased rates of termination of pregnancy (TOP) in fetuses with orofacial clefts (OFCs). The aim of this study was to evaluate the impact of a nationwide introduction of SAS on the prevalence of live births with OFCs in the Netherlands.Retrospective cohort study.Tertiary setting.Included in the study were all patients diagnosed with OFCs as recorded in the "Dutch Association for Cleft Palate Anomalies" database between 1997 and 2019.Patients were divided into three categories: cleft lip with or without alveolus (CL/A), cleft lip, alveolus and palate (CLAP) and cleft palate (CP) based on anatomical landmarks at the first consultation.Prevalence rates of OFCs before and after the nationwide introduction of the SAS on January 1, 2007 were compared.Overall, 1899 patients were diagnosed with CL/A, 2586 with CLAP and 2927 with CP. The prevalence of clefts before and after introduction of the SAS did not differ (P = 0.85). The prevalence of CL/A decreased (P = 0.04), and that of CLAP decreased (P = 0.01) and that of CP increased (P = 0.02).This study demonstrates a significant decrease in the prevalence of CL/A and CLAP after introduction of the SAS. However, due to an increase in CP, the prevalence of all patients born with OFCs has not changed in the Netherlands between 1997 and 2019.