Birth prevalence of congenital anomalies in Argentina, according to socioeconomic level.

Birth prevalence of congenital anomalies (CA) in Argentina is estimated around 1.7%. CA are the second leading cause of infant mortality. Poverty and other adverse socioeconomic conditions have been associated with birth defects. To describe the prevalence at birth of CA, according to the two proxy variables of socioeconomic level: the health subsector of the hospital where the cases were born (PUB-public versus PRI-private or social security) and its geographical location. The design of the study was ecological using the data of the National Network of Congenital Anomalies of Argentina (RENAC); from October 2010 to December 2018. CA birth prevalence was estimated using the Poisson regression. We used a logistic regression model to analyze the association birth prevalence to health subsector and geographical region. A total of 2,202,994 births were examined in the study period, with a global CA prevalence of 1.69% (95% CI 1.68-1.71). The highest prevalence was observed in PUB hospitals when comparing to PRI hospitals at the country level and in all regions. There were differences in the prevalence of selected congenital anomalies with a statistically significant association to PUB (observed in anencephaly, encephalocele, hydrocephalus, microcephaly, holoprosencephaly, microtia/anotia, cleft lip and palate, postaxial polydactyly, talipes equinovarus, talipes calcaneovalgus, and gastroschisis). The prevalence of critical heart defects and chromosomal anomalies was significantly higher in PRI hospitals. Although this is an ecological study with no information on socioeconomic status at individual level, we found an association between CA frequency and selected CA with the PUB subsector. Vulnerable populations affected with CA require a greater effort from policy makers and health care providers to allocate more resources and design strategies to access to health.