Can prenatal detection of Down syndrome be improved by enhancing obstetricians' skills of performing adequate foetal cardiac examination at the primary level?

AIMS: To evaluate the prevalence of congenital heart defects (CHDs) in live-born infants with Down syndrome (DS) and to investigate whether these CHDs might be detected during routine second trimester ultrasound screening performed at the primary level.

METHODS: A retrospective analysis of 66 cases of DS in live-born infants. The infants with DS underwent a detailed echocardiographic examination to evaluate cardiac morphological characteristics and function.

RESULTS: Thirty-six live-born DS infants (54.5%) had associated CHDs. According to the apical four-chamber view at the first postnatal echocardiographic examination, we estimated that 20 (55.6%) of the 36 patients with associated CHDs should have been identified during the routine second-trimester prenatal scan [17 infants with complete atrioventricular septal defect (AVSD), two with partial AVSD, and one with non-restrictive perimembranous ventricular septal defect] if the results had been correctly interpreted. An additional seven patients with associated CHDs should have been identified if the evaluation of both outflow tracts had been included into the screening protocol.

CONCLUSION: Our data suggest that the prenatal DS detection rate can be significantly increased by improving obstetricians' skills of performing adequate foetal cardiac examination as part of the routine 18- to 23-week ultrasound examination at the primary level.