Birth Outcomes of Cases with Single Ventricle Complex – A Population-Based Case-Control Study

Aims: The aim of this paper was to study the birth outcomes of cases with single ventricle complex (SVC), a rare congenital heart defect, as homogeneously as possible.

Study Design: For the analysis of cases, the large dataset of the population-based Hungarian Case-Control Surveillance of Congenital Abnormalities was used.

Place and Duration of Study: The study was conducted in Budapest based on the data set of the HCCSCA between 1980 and 1996 but the follow-up of cases was performed in 2008-2011.

Methodology: Syndromic/multiple cases with the component SCV were excluded and only live-born cases based on autopsy report in lethal cases and on medical documents after surgical correction were included to the study. Medically recorded birth outcomes of 76 cases with SVC and 38,151 population controls without defect were compared but maternal socio-demographic variables as confounders were considered.

Results: A higher rate of twins (5.3% vs. 1.0%; OR with 95% CI: 5.11, 1.55-12.40) was observed in cases compared to population controls. The rate of low birthweight (18.4% vs. 5.7%; OR with 95% CI: 4.84, 2.23-9.71) was higher in cases than in population controls. Among maternal variables the higher birth order 3 or more (25.0% vs. 14.8%, p=0.04) and pregnancy order (p = 0.0005) are noteworthy, the latter is explained by the higher rate of miscarriages in previous pregnancies of case mothers.

Conclusion: The higher rate of twins and low birthweight suggest some association with the origin of SCV.