We present the antenatal cardiac findings in an infant in whom a postnatal diagnosis of congenital disorder of glycosylation type Ia (CDG-Ia) was confirmed. The antenatal findings at 34 weeks’ gestation included biventricular cardiac hypertrophy with pericardial effusion, multiple skeletal anomalies and cerebral ventricular dilatation. A severe CDG-Ia multisystem clinical phenotype evolved in the postnatal period, with the infant succumbing at 3.5 weeks of age secondary to a large pericardial effusion with tamponade. A literature review suggests that this is the first case of cardiac manifestations of CDG-Ia observed antenatally. We would also like to suggest that CDG-Ia should be considered and if possible prenatal diagnosis performed in cases with hypertrophic cardiomyopathy, and/or pericardial effusion.