P113Prenatal diagnosis of congenital heart defects: report of 263 cases

Abstract

AimTo evaluate the main characteristics of prenatally diagnosed congenital heart defects (CHD).MethodsRetrospective study of 263 fetuses with CHD diagnosed between January 1993–September 1999. In this period 133 more cases were born with a CHD not identified prenatally.ResultsThe incidence in the period reviewed was 1/148 deliveries (7‰). 161 patients (61%) were referred from other Hospitals. Mean gestational age at diagnosis was 27.1 weeks (range: 13–41). 103 were diagnosed before 22 weeks (39%). Most common CHD were complete atrioventricular canal (CAVC) (49 cases, 18%), hypoplastic left heart syndrome (HLHS) (37,14%) and conotruncal anomalies (CTA) (31, 12%). Postnatally, most common CHD were ventricular septal defects (VSD) (70, 29%). Overall sensitivity was 66%, improving from 1993 (60%) to 1999 (80%). Sensitivity was higher for CAVC (86%), HLHS (90%), tricuspid atresia (93%). Sensitivity was poor in VSD (26%). Associated anomalies were seen in 105 cases (40%) more common in CAVC (37/49, 75%), VSD (16/22, 73%) and CTA (14/31, 45.2%). In 85 cases (32%) termination of pregnancy (top) was performed. This represents 82.5% of 103 cases diagnosed < 22 weeks' gestation. tops were more common in CAVC (39%) and HLHS (46%).ConclusionFetal echocardiography enables the diagnosis of a high number of CHD in the first half of pregnancy. Changes in the monographic visualization of the CHD over the pregnancy with potential progression of the lesion in utero, the small size of the defect and difficulties in monographic work‐up are explanations for late diagnosis and false negative cases. The distribution of the different CHD differs from that observed postnatally. Associated anomalies should be ruled out because of their high frequency, mainly in some specific heart defects.