Clinical implication of isolated right dominant heart in the fetus

To evaluate the clinical implication of isolated right dominant heart (RDH) in fetal echocardiography.

We reviewed the medical records of pregnant women diagnosed with fetal RDH at Asan Medical Center from December 1999 to December 2005. The criteria of RDH were the ratio of right-to-left atrial and ventricular width and the ratio of the diameter of pulmonary artery-to-aorta were greater than 1.5. Fetuses with congenital heart disease, including coarctation of the aorta (CoA), noncardiac anomalies or chromosomal abnormalities were excluded.

RDH was identified in 44 fetuses. Twenty-nine (66%) were confirmed to have normal heart and 15 (34%) had cardiac anomalies by postnatal echocardiogrphy; 11 CoA, 1 interruption of aortic arch, 1 patent ductus arteriosus, and 2 ventricular septal defect. Mean gestational age at presentation with RDH was later in normal fetuses as compared to fetuses with CoA (p < 0.005). Only 26% (4/15) of fetuses presenting with RDH during the second-trimester were found to have normal heart postnatally, compared with 86% (25/29) of those diagnosed in the third-trimester.

RDH in the fetus is a risk factor for postnatal CoA particularly when diagnosed in the second-trimester, and should be an indication for neonatal echocardiography.