Ultrasound Screening in the First and Second Trimester of Pregnancy for the Detection of Fetal Cardiac Anomalies in a Low-Risk Population

<b>Background/Objectives:</b> Congenital heart disease (CHD) is the most common birth defect, an important cause of morbidity and mortality, with a reported prevalence of 5-12 per 1000 live births. The aim of our study was to identify the role of fetal morphological ultrasound examination in the first and second trimester of pregnancy in the detection of fetal congenital cardiac anomalies in a low-risk population. <b>Methods:</b> We performed a retrospective study in a tertiary fetal medicine center in Emergency Hospital Craiova, Romania. The longitudinal analysis combined first- and second-trimester screening using improved ultrasound protocols. Our study evaluated 8944 pregnant women with singleton pregnancies in a 6-year period between January 2018 and December 2023. All ultrasound examinations were performed using a standard extended protocol according to the main guidelines' recommendations for the detection of fetal anomalies. <b>Results:</b> In the first trimester of pregnancy, 37 cases with cardiac anomalies were diagnosed. Thirteen of these cases were associated with genetic anomalies (Down syndrome-eight cases, Edwards syndrome-four cases, Turner syndrome-one case). Some of these pregnancies were associated with at least one of the minor ultrasound markers (inverted ductus venosus, abnormal flow in the tricuspid valve, presence of choroid plexus cysts, absent/hypoplastic nasal bone). In the second trimester of pregnancy, 17 cases of cardiac anomalies were diagnosed. From these cases, one was associated with genetic anomalies (DiGeorge Syndrome), and one case developed hydrops and delivered prematurely in the early third trimester. <b>Conclusions</b>: Ultrasound screening for the detection of congenital heart disease is feasible early in pregnancy, but some anomalies would be obvious later in pregnancy. An early diagnosis using an extended ultrasound protocol, genetic testing, and a multidisciplinary evaluation would improve the prognosis and the overall survival rate by delivering in a tertiary center that allows for rapid cardiac surgery in dedicated cases.