Prenatal diagnosis of Shone's syndrome: parental counseling and clinical outcome.

OBJECTIVE: To describe a series of fetuses diagnosed as having Shone's syndrome, which includes four cardiac defects and for which there is a wide variety of clinical presentations, surgical treatments and outcomes, and to discuss the counseling strategy.

METHODS: We reviewed retrospectively the records of four babies who were suspected prenatally to have Shone's syndrome.

RESULTS: The mean age at diagnosis was 27.5 (range, 22-35) weeks. A small left ventricle, mitral and aortic annulus and ascending aorta were detected in three cases. In three fetuses there was an abnormal mitral valve apparatus and in two fetuses a sub-aortic membrane was detected. Coarctation of the aorta was an impending diagnosis in three babies. Following counseling, all parents decided to continue the pregnancy to term. Echocardiographic evaluation was performed soon after birth. The mean mitral valve annulus diameter was 8.2 (range, 7-10) mm, and that of the aortic valve annulus was 6 (range, 5-7) mm. The aortic valve was bicuspid in all babies with an additional sub-aortic membrane in two babies. Doppler ultrasound examination revealed high-velocity flow through the mitral valve in three babies; two of them had a parachute mitral valve. Coarctation repair was performed in two babies during the first week of life. One patient underwent mitral valvuloplasty followed by later mitral valve replacement. All patients were alive after a mean of 7.8 (range, 3.3-10.5) years' follow-up.

CONCLUSION: When counseling families regarding fetal Shone's syndrome, it is important to emphasize the wide variety of clinical presentations and possible outcomes. Differentiation between hypoplastic left ventricle and Shone's complex is crucial and may influence the physician's attitude, the presentation of the case to the family and the family's final decision.