Birthweight and isolated congenital heart defects - A systematic review and meta-analysis

Background Birthweight (BW) is an important prognostic factor in newborns with congenital heart defects (CHD). Objectives To give an overview of the literature on BW z-score in children with isolated CHD. Search strategy A systematic search was performed on isolated CHD and BW in PubMed, Embase, Web of Science, COCHRANE Library and Emcare. Selection criteria Neonates with isolated CHD were included if a BW percentile, BW z-score or % small-or-gestational age (SGA) was reported. Data collection and analysis BW z-score and percentage SGA were pooled with random-effect meta-analysis. Quality and risk of bias were assessed using the modified Newcastle Ottawa Scale. Main results Twenty-three articles (27 893 cases) were included. BW z-scores were retrieved from 11 articles, resulting in a pooled z-score of -0.20 (95% CI -0.50 to 0.11). The overall pooled prevalence of SGA <10th percentile was 16.0% (95% CI 11.4-20.5; 14 studies). Subgroup analysis of major CHD showed similar results (BW z-score -0.23 and percentage SGA 16.2%). Conclusions Overall BW in isolated CHD is within range of normality but impaired, with a 1.6-fold higher risk of SGA, irrespective of the type of CHD (major CHD vs all CHD combined). Our findings underline the association between CHD and BW. The use of BW z-scores provides insight into growth of all fetuses with CHD.