OBJECTIVES: to investigate changes over time and factors associated with caesarean section rates in the State of Santa Catarina, Brazil, between 2000 and 2004. METHODS: data from the Live Births National Information System for the State of Santa Catarina were used. The variables analyzed were maternal age and literacy, ethnicity/skin color of the newborn, duration of gestation and number of prenatal consultations. Crude and adjusted prevalence rates were estimated for each of the variables using Poisson regression. RESULTS: rates for the period were three times higher of those accepted by the World Health Organization and increased from 43.3% in 2000 to 50.6% in 2004. For the whole period (2000-2004) prevalence rates, both crude and adjusted, were found to be positively associated with higher maternal literacy (PRadj=1.50; 95%CI: 1.47-1,52), older age (PRadj=2.10; 95%CI: 2.05-2.15), greater number of prenatal consultations (PRaj=1.27; 95%CI: 1.26-1.29), pre-term (PRadj=1.10; 95%CI: 1.06-1.13) and post-term deliveries (PRadj=1.22; 95%CI: 1.14-1.30), and protection for the indigenous (PRadj=0.79; 95%CI: 0.75-0.85) and "non-white" newborns (PRadj=1.10; CI95%: 1.06-1.14). A significant decrease in the adjusted prevalence ratios (PRs) when comparing the extremes in the period (2000 and 2004) appeared for all variables and categories. CONCLUSIONS: the caesarean section rates were well above those justified for medical reasons alone. The decrease in the caesarean section PRs when comparing extremes during the period calls attention to a reduction in the effects of the "inverse equity" probably connected to a higher access to childbirth technology among women of lower socio-economic status, at least partly attributable to more liberal use of this technology in obstetrical practice, including more widespread medical recommendation of caesarean section.
Cesarean Section; Risk factors; Health inequalities; Socioeconomic factors; Ethnic groups; Educational status; Maternal age; Women's health; Indigenous population
