Congenital limb reduction defects in 1.6 million births in Argentina.

The objectives of this study were to describe the birth prevalence of limb reduction defects (LRD) in Argentina, their clinical features, and to review the literature on this topic. The data source was the National Network of Congenital Anomalies of Argentina, a surveillance system that has been operative since 2009. Data were collected from November 1, 2009 to December 31, 2016. 1,663,610 births and 702 affected patients were registered during this period. The prevalence of LRD was 4.22/10,000 births (CI 95%: 3.93-4.54). In 15,094 stillbirths, prevalence was 30.80/10,000 (CI 95%: 22.31-40.65). Perinatal mortality (stillbirths plus early neonatal deaths) was 24.6%, mostly explained by postnatal deaths. LRD were classified according to different variables, including Gold's anatomic classification. Then, 41.0% of patients had transverse terminal defects and 50.2% had longitudinal defects. We found multiple and syndromic clinical presentation to be associated with both preaxial LRD and lethality. The prevalence of LRD was lower and perinatal mortality was higher in our study compared to that of previously published studies. Because there is heterogeneity in the inclusion and exclusion criteria among publications, a greater effort should be made in order to include similar populations and to use a unified anatomic classification and nomenclature.