Prevalence and mortality of congenital heart defects in Tuscany region, 1992-2009

Background Congenital heart defects (CHDs) are the most common congenital anomalies and the main cause of mortality in newborns and in infants. To estimate the prevalence of CHDs according to their severity is crucial to plan health care services and to set up specific preventive actions in order to improve the management of this health problem. Advances in cardiovascular medicine and surgery have led to an increased survival of the newborns with CHDs. Nevertheless, the impact of the prenatal diagnosis on the prevalence at birth, providing the option for pregnancy termination mostly for severe CHDs, is well established. Objective The aim of the study is to estimate the prevalence and mortality of All CHDs and Nonchromosomal CHDs (NCHRCHD), in Tuscany from 1992 to 2009, and to compare two sub-periods. Methods Data collected by the population-based EUROCAT Registry of Birth Defects of Tuscany, were used. They regarded live births (LBs), fetal deaths (FDs), terminations of pregnancy for fetal anomaly (TOPFA), prenatal diagnosis (PD), perinatal and neonatal mortality. All cases were coded according to the ICD9-BPA or ICD-10. The NCHRCHD cases were classified in three severity subgroups: SI, SII, SIII (according to decreasing perinatal mortality). The NCHRCHD cases were classified into isolated or associated according to the presence or absence of an additional major non-cardiac anomaly. Results 3,653 CHD cases were identified among 488,890 births monitored from 1992 to 2009 for an overall prevalence of 7.47 per 1,000. LBs prevalence decreased significantly (Rate Ratio RR=0.81 95%CI:0.76-0.87), while TOPFA prevalence increased more than 2-fold (RR=2.56 95%CI:1.80-3.71) as well as PD cases (RR=2.13 95% CI:1.75-2.61). The rate of perinatal and neonatal mortality significantly reduced (RR=0.38 95%CI:0.23-0.60; RR=0.34 95%CI:0.22-0.51). 3,465 NCHRCHD cases were ascertained with a prevalence of 7.09 per 1,000. The LBs prevalence decreased significantly (RR=0.82 95%CI:0.77-0.88). TOPFA prevalence increased by almost 3-fold (RR= 2.63 95%CI:1.75-4.05), PD cases doubled (RR=2.29 95%CI: 1.84-2.88). Neonatal mortality was slightly lower than the perinatal (RR=0.29 95%CI:0.18-0.46; RR=0.37 95%CI: 0.22- 0.61). SI and SII CHDs combined were approximately a quarter (N=765; 22.1%) of the total cases, with a stable total prevalence over time (RR=0.98 95%CI:0.84-1.13) and a 17% significantly decreasing of LBs prevalence. LBs with CHDs (more than 90% isolated) were 72% in SI, 92% in SII, 99% in SIII. Overall, more than 90% of TOPFA occurred in SI and SII classes. Only 10% of TOPFA cases had an associated anomaly in SI, almost 50% in SII. Conclusions In the more severe CHDs a strong increase of prenatal diagnosis is associated with a remarkable rising of termination of pregnancy and a significantly decrease of perinatal and neonatal mortality. Notwithstanding the decreasing of LBs prevalence of more severe CHDs, their impact remains relevant and interventions strategies should take it into account. All these information are needed to plan high-quality services and to monitor the progress in prevention.