[Differences in live birth clusters in the city of São Paulo, Brazil, 2010]

This study aimed to identify birth clusters according to type of hospital (SUS vs. non-SUS) and the existence of differences in socioeconomic, maternal, neonatal, and healthcare access characteristics, measured by the distance between the mothers' homes and the hospitals where they gave birth. Births to mothers residing in the city of São Paulo, Brazil, in 2010 were georeferenced and allocated in 310 weighting areas from the population census, in addition to classifying them according to hospital of birth (SUS vs. non-SUS). Spatial clusters were identified through the spatial sweep technique for spatial dependence of SUS and non-SUS births, leading to the formation of ten SUS clusters and seven non-SUS clusters. Births in non-SUS hospitals formed clusters in the city's central area, with a lower proportion of low-income households. The SUS birth clusters were located on the outskirts of the city, where there are more households in subnormal clusters. Both SUS and non-SUS clusters were not internally homogeneous, showing differences in maternal age, schooling, and number of prenatal visits and very premature newborns. The theoretical mean distance traveled by mothers to the hospital was 51.8% lower in the SUS clusters (5.1km) than in the non-SUS clusters (9.8km). The formation of birth clusters showed differences in maternal, pregnancy, childbirth, and neonatal characteristics, in addition to displaying a radial-concentric spatial distribution, reflecting the city's prevailing socioeconomic differences. The shorter distance in SUS births indicates regionalization of childbirth care in the city of São Paulo.