Basics French Guiana is an overseas department with diverse population composition. Despite its integration in a European model, there are social issues and high infant mortality, with unknown congenital Heart Disease (CHD) prevalence.

Fetal screening, terminations of pregnancy (TOPFA), prevalence, associated chromosomal or genetics anomalies (CGA) and infant mortality of all CHD diagnosed in French Guiana are compared to published data from greater Paris (EPICARD population study, France).

Five-year retrospective study including all patients with CHD born in French Guiana from January 2012 to December 2016, as well as CHD diagnosed during pregnancy over the same period. The last cases included were those in the 2016 birth cohort who were diagnosed in 2017.

Over 33,796 births [32,975 live births (LB)] during the study period, a total of 231 CHD (56 fetuses), with 18.6% of CGA, were diagnosed including 215 LB (TOPFA rate: 6.5%). The total and the LB prevalence of CHD were 68.4 [95% confidence interval (CI): 67.9–68.8], and 65.2 [95% CI: 64.7–65.7] per 10,000. Having excluded CGA and isolated ventricular septal defects (VSD), the LB prevalence of CHD appeared similar in both regions, while the total prevalence (8/10,000 births, P=0.03) and LB prevalence (3.9/10,000 LB, P<0.002) of univentricular hearts were higher. The total infant mortality associated with CHDs in French Guiana is 9.4/10,000 LB, and represents twice the one observed in greater Paris (P=0.0005). Such difference appears only related (P=0.0008) to the higher prevalence of univentricular hearts.

This study demonstrated for the first time a higher prevalence of univentricular hearts in French Guiana which represents the main current cardiac cause of infant mortality. This act as a significant marker of the global burden of complex CHD in this region Furthers studies are required to extend such findings to surrounding countries of South America.