Congenital heart disease (CHD) is the leading cause of infant mortality. Nevertheless, routine prenatal ultrasound only detects 30 %-50 % of CHD cases. Therefore, emphasis should be placed on early predictors of CHD that allow physicians to timely refer high-risk patient to specialized fetal echocardiography, in order to maximize chances of improved outcomes. The fetal venous system has been the focus of attention as a marker of heart function. Yet, there exist inconsistent data about the acquisition of pulmonary venous flow in early pregnancy. This study aims to determine the feasibility of fetal pulmonary venous flow acquisition in early pregnancy, and the association between pulmonary vein (A-wave) flow reversal and the presence of CHD. Total of 211 consecutive pregnant women, between 12 and 15 weeks of gestation, underwent routine obstetric ultrasound along with basic fetal echocardiography including fetal pulmonary venous flow assessment. The pulmonary venous flow velocity waveforms were acquired by either Doppler or Doppler plus enhance flow technique based on equipment availability. All the cases were re-evaluated by specialized fetal echocardiography during late pregnancy to identify congenital heart anomalies. The acquisition of fetal pulmonary vein, between 12 and 15 weeks of gestation, was successfully accomplished in 87.7 % of cases. Five out of seven fetuses with end-diastolic (A-wave) pulmonary venous flow reversal were associated with confirmed cardiac anomaly. In this pilot study, pulmonary venous (A-wave) flow reversal was associated with cardiac anomalies in 86.8 % of cases (p = 0.001). This pilot study proposes that Doppler interrogation of fetal pulmonary vein flow during early pregnancy is feasible. Furthermore, the presence of pulmonary vein (A-wave) reversal might represent a marker of major cardiac anomalies. Further investigation is needed to confirm these findings.

Background Improvements in congenital heart disease (CHD) screening are needed based on the lack of sensitivity of current screening methods and the understanding that the early detection of certain CHDs may improve outcomes. Fetal venous circulation has caught medical attention, and two studies demonstrated that it is feasible to register pulmonary vein flow velocity waveforms (FVWs) during early gestation. Meanwhile, the latter study proposed pulmonary vein A-wave reversal as a marker of cardiac anomaly. Methods We report a series of six consecutive fetuses with confirmed cardiac anomalies that underwent first-trimester screening, including pulmonary vein FVWs, at our center during 2013. CHD was confirmed by late pregnancy echocardiography, and in three cases fetal autopsies were performed. Result/Discussion The ductus venosus (DV) and nuchal translucency (NT) predicted 50% of CHD cases, whereas the combination of markers identified 66.6% of CHD cases. When adding pulmonary vein assessment, the rate of detection rose to 83.3%. Total five of six cases of CHD had reversal of pulmonary vein A-wave during early pregnancy. The sixth case with CHD and nonreversal of A-wave was described as right ventricle hypoplasia with type 1 tricuspid atresia and persistent ductus arteriosus. Conclusion This is the first series reporting pulmonary vein end-diastolic reversal as a CHD screening add-on during early pregnancy. The addition of pulmonary vein FVW assessment to the current CHD screening bundle could increase the rate detection of cardiac anomalies. This pilot study suggests that pulmonary vein end-diastolic flow reversal favors detection of left-sided CHD over the right-sided ones.