Fetal congenital heart disease and intrauterine growth restriction: a retrospective cohort study

Objective: Fetal congenital heart disease may lead to abnormal fetal growth. Our objective was to estimate the association between fetal congenital heart disease (CHD) and intrauterine growth restriction (IUGR) in an effort to better inform clinical management of continuing pregnancies complicated by fetal congenital heart disease. Methods: In a retrospective cohort study, outcome data was collected from singleton pregnancies undergoing routine anatomic survey at a tertiary medical center between 1990 and 2008. Dedicated research nurses collected information on delivery outcomes in an on-going manner. Subjects with a prenatal diagnosis of fetal CHD were compared to those without CHD. Stratified analyses for isolated fetal CHD and major CHD were performed. The primary outcome was IUGR less than 10th percentile by the Alexander growth standard. Logistic regression was used to adjust for confounding variables and refine the estimates of risk. Results: Among 67,823 patients, there were 193 cases of fetal CHD (0.3%) and 5,669 cases of IUGR (8.4%). Prenatal diagnosis of CHD was associated with an increased risk of IUGR (23.8% vs. 8.5%, adjusted odds ratio [aOR] 3.3, 95% confidence interval [CI] 2.4-4.6), and the risk was greatest in fetuses with major CHD (16.5% vs. 8.5%, aOR 2.1, 95% CI 1.3-3.2). Isolated CHD was also associated with an increased risk of IUGR (17.8% vs. 8.5%, aOR 2.2, 95% CI 1.4-3.7). Conclusion: Patients with a prenatal diagnosis of fetal CHD have a three-fold increase in risk of developing IUGR; patients with isolated fetal CHD are twice as likely to develop IUGR. Based on our findings, serial growth assessment may be a reasonable option for patients with fetal CHD diagnosed at routine anatomic survey.