Objective: In this study, we aimed to investigate the efficiency of first trimester fetal heart examination. Methods: This study was carried out prospectively on the pregnant women admitted for the screening of first trimester chromosomal anomaly to the perinatology clinic between August 2016 and February 2018. The cardiac examination was performed by obtaining abdominal situs screening and the four-chamber and three-vessel (3-V) views. The cases found to have cardiac anomaly were followed up. The patient data and results were recorded. Descriptive statistical analyses were performed.

Results: A total of 707 fetuses in 693 pregnancy cases were examined in this study. While the fetal heart examinations were performed by the transabdominal ultrasonography in 661 cases, the necessary images could not be obtained in the examinations of 32 (4.6%) cases, and the assessment was done by transvaginal ultrasonography. Abnormal cardiac findings were found in 10 cases. The diagnosis could not be validated in 3 cases and they were considered having normal hearts, and the false positivity was found in 0.4%(3/698) of the cases. The aneurysm of restrictive foramen ovale was found in two cases whose first trimester examinations were considered normal. The sensitivity, specificity, positive predictive value and negative predictive value of four-chamber and three-vessel (3-V) image for detecting the cardiac anomalies in the first trimester heart examination were 77%, 99.5%, 70% and 99.7%, respectively. Conclusion: A great number of cardiac anomalies can be diagnosed by four-chamber and three-vessel (3-V) cross-sections in the first trimester. Also, it should be kept in mind that there may be false positivity and false negativity in the first trimester heart examinations even with low rates and some cardiac anomalies can be seen or detected only in the further weeks of gestation, and the families should be informed accordingly.