ABSTRACT

Objective: To evaluate the effectiveness of adding outlet views to the four chamber view in routine prenatal ultrasound screening for major congenital heart defects (CHD) as performed by trained sonographers, and to compare the procedure with current practice. Design and setting: Prospective observational study at a London teaching hospital. Participants and methods: 9277 women booked at a single institution (80% had first trimester nuchal translucency measurement) due to have routine fetal cardiac screening using the four chamber and outflow tract views at > 18 weeks of gestation. Main outcome measure: Identification of major CHD in chromosomally normal and abnormal pregnancies antenatally or postnatally. Results: There were 40 abnormalities (4.3/1000), of which 30 were chromosomally normal (3.3/1000). The overall antenatal detection rate was 75% (95% confidence interval (CI) 59% to 87%) and 70% (95% CI 51% to 85%) for euploid pregnancies. Abnormal cardiac views accounted for 70% of all prenatal diagnoses, 30% of which were made at < 18 weeks. The sensitivity of cardiac views during the first scan at > 18 weeks was 52%. Of all patients undergoing nuchal translucency screening, 34 had major CHD, nine with increased nuchal translucency (26.5%). Factors influencing the results of this screening programme were training and audit of operators, adequate equipment for antenatal examination, ease of access, and low threshold for referral to specialised fetal echocardiography. Conclusion: Adding ventricular outlet views to the four chamber assessment of the heart at routine fetal anomaly scans at > 18 weeks is the most effective technique to detect CHD prenatally. The success of such a programme depends on an infrastructure committed to continuous in house training of obstetric ultrasonographers coupled with feedback from specialised fetal cardiologists, as well as adequate resource allocation to obstetric hospitals involved with antenatal screening.

Background-Fetal tachyarrhythmia may result in low cardiac output and death. Consequently, antiarrhythmic treatment is offered in most affected pregnancies. We compared 3 drugs commonly used to control supraventricular tachycardia (SVT) and atrial flutter (AF). Methods and Results-We reviewed 159 consecutive referrals with fetal SVT (nϭ114) and AF (nϭ45). Of these, 75 fetuses with SVT and 36 with AF were treated nonrandomly with transplacental flecainide (nϭ35), sotalol (nϭ52), or digoxin (nϭ24) as a first-line agent. Prenatal treatment failure was associated with an incessant versus intermittent arrhythmia pattern (nϭ85; hazard ratio [HR]ϭ3.1; PϽ0.001) and, for SVT, with fetal hydrops (nϭ28; HRϭ1.8; Pϭ0.04). Atrial flutter had a lower rate of conversion to sinus rhythm before delivery than SVT (HRϭ2.0; Pϭ0.005).Cardioversion at 5 and 10 days occurred in 50% and 63% of treated SVT cases, respectively, but in only 25% and 41% of treated AF cases. Sotalol was associated with higher rates of prenatal AF termination than digoxin (HRϭ5.4; Pϭ0.05) or flecainide (HRϭ7.4; Pϭ0.03). If incessant AF/SVT persisted to day 5 (nϭ45), median ventricular rates declined more with flecainide (Ϫ22%) and digoxin (Ϫ13%) than with sotalol (Ϫ5%; PϽ0.001). Flecainide (HRϭ2.1; Pϭ0.02) and digoxin (HRϭ2.9; Pϭ0.01) were also associated with a higher rate of conversion of fetal SVT to a normal rhythm over time. No serious drug-related adverse events were observed, but arrhythmia-related mortality was 5%. Conclusion-Flecainide and digoxin were superior to sotalol in converting SVT to a normal rhythm and in slowing both AF and SVT to better-tolerated ventricular rates and therefore might be considered first to treat significant fetal tachyarrhythmia. (Circulation. 2011;124:1747-1754.)