The incidence of congenital heart defects in very low birth weight and extremely low birth weight infants.

Background: The incidence of congenital heart defects, reported to be 5-8/1000 in term infants, is not well established in very low birth weight infants.
Objectives: To establish the incidence of congenital heart defects in VLBW infants in the neonatal intensive care unit of our institution.
Methods: A retrospective analysis of the population in the NICU at our institution was performed. VLBW (BW < or = 1500 g) infants born between 2001 and 2006 who survived more than 48 hours were included in the study. Infants with clinical signs of heart disease underwent echocardiography.
Results: During the study period 437 VLBW live-born infants met the inclusion criteria. Of these, 281 (64.3%) underwent echocardiography. CHD was detected in 19 infants (4.4%, 95% confidence interval 2.4-5.4%), significantly higher than the incidence of 5-8/1000 in the general population (P<0.0001). In the subgroup of 154 infants with BW < 1000 g there were 10 (6.5%) with CHD. In the subgroup of 283 infants with BW 100-1500 g there were 9 (3.2%, P= 0.19 vs. VLBW) with CHD.
Conclusions: Our observations show an increased incidence of CHD in VLBW neonates, as compared to the general population. Since not all infants underwent echocardiography, and minor cardiac defects may have been missed in our VLBW infants, the true incidence may be higher than reported here.