Systematic review and meta-analysis of the performance of second-trimester screening for prenatal detection of congenital heart defects

Background: The prenatal detection rate of congenital heart defects (CHDs) is increasing, but reported rates vary. Objectives: To determine the performance of the second-trimester anomaly scan to detect CHD. Search strategy: PubMed and Embase were searched for relevant studies in any language from inception to February 3, 2017. The search terms included "prenatal diagnosis" or "pregnancy," "cardiovascular diseases" or "cardiac defects," "congenital," and "specificity," or "sensitivity," or "cohort study." Selection criteria: Cohort studies assessing the detection rate of CHD during population-based prenatal screening from 1995 were eligible for inclusion. Data collection and analysis: Data were collected from identified studies; authors were approached for additional data when necessary. A review and meta-analysis were performed. When possible, separate analyses were undertaken for isolated CHD cases. Main results: Meta-analysis of seven studies showed the pooled detection rate of CHD in unselected populations as 45.1% (95% confidence interval 33.5%-57.0%). However, the rate of detection of univentricular defects and heterotaxy was above 85%. Similar rates were found among cases of isolated CHD. Conclusions: Prenatal detection showed a strong correlation with CHD severity. The detection of conotruncal anomalies needs to improve. A thoroughly organized screening program will be essential to achieve a higher detection rate.