The prevalence of congenital cardiac tumours in unselected newborns

Abstract Background Primary cardiac tumours in children are rare. The most common cardiac tumour in newborns is rhabdomyomas, associated with tuberous sclerosis in >50% of cases. The estimated prevalence is 0.14‰ in fetuses, whereas in the paediatric population, a 20-fold difference in autopsy prevalence has been reported (0.017‰ to 0.27‰). Purpose To determine the pre- and postnatal prevalence of congenital cardiac tumours in a large, population-based cohort of prenatally enrolled newborns. Methods Systematic transthoracic echocardiography (TTE), including sub-xiphoid, apical, parasternal, and suprasternal views, was performed in unselected newborns included in a population study. Participants were included at time of the routine malformation scan (weeks 18-21), which included 4-chamber view, aortic and pulmonary outflow tracts, and three-vessel view. Cardiac tumours were defined as solid, echogenic masses, and the echocardiographic description included location, size, and number (one/multiple) of the tumour. Information on subsequent diagnosis of tuberous sclerosis was collected from review of medical charts. Results A total of 25,588 newborns (age 12±8 days, 51.6% male) were enrolled and underwent TTE. Prenatally, no cardiac tumours were reported in any of the participants. Postnatally, cardiac tumours were detected in 7 newborns (4 males), corresponding to a prevalence of 0.3 [0.1; 0.6] per 1,000 live-births. Through retrospective review of the prenatal scans, a possible tumour in the ventricle was suspected in 1 of the 7 cases; the remaining 6 cases showed no signs of tumours prenatally. Sex, gestational age at birth, birth length and weight, APGAR 5-score, age and weight at TTE, and maternal age and pre-pregnancy BMI, did not significantly differ between newborns with (n=7) and without (n=25,581) cardiac tumours (all p>0.05). Smoking during pregnancy was significantly more frequent among mothers to newborns with cardiac tumours compared to the remaining cohort (29% vs 4%, p=0.023). In all 7 newborns, the cardiac tumours were located in the ventricles (5 (71%) newborns with tumours in both ventricles, 2 (29%) with tumours in the right ventricle), with multiple tumours seen in 6 (86%), and with size ranging from 2.0x1.9 mm to 10.0x5.1 mm. All 7 newborns had otherwise structurally normal hearts and no flow obstruction. Three newborns with cardiac tumours in the ventricles (43%) were diagnosed with tuberous sclerosis within 4 months after birth. Conclusions Systematic TTE in unselected newborns revealed a prevalence of congenital cardiac tumours of 0.3‰. Prenatal screening in week 18-21 did not seem efficient for identification of cardiac tumours. Cardiac tumours were located in the ventricles and were most often multiple. Cardiac tumours in the ventricles were associated with tuberous sclerosis in almost half the cases. For newborns with cardiac tumours, maternal smoking during pregnancy was common (29%).Figure 1