Births in Brazil: association between type of delivery and temporal and socio-demographic variables

Objectives:  to identify caesarean and vaginal births and their association with temporal and socio-demographic variables.

Methods:  a mixed approach involving descriptive time series studies (2000, 2005, 2010) and one cross-sectional study (2011), using data from the Live Births Information System. The data were corrected for under-reporting; the type of birth was analyzed in terms of day of the week, time of the day, area of residence, race/color, level of education and marital status of mother. Raw and adjusted probability ratios for surgical births were calculated using Poisson regression.

Results:  the proportion of caesarean births in the country increased around 40% from 2000 to 2010. Vaginal births were distributed similarly over the days of the week (around 14% for each day) and according to time of day (around 25%), while caesareans were concentrated on week days and during the daytime. The proportion of caesareans was lower in the Northern region (42.8%), among the indigenous population (16.2%), among women with no schooling (25.2%) and among single mothers (42.0%), with a tendency to increase in proportion to age and level of schooling. After adjustment, the Center West region had the highest proportion of caesarean births with the same associated variables.

Conclusions:  the proportion of caesarean births in the country is over 50% and is associated primarily with age and level of education of the mother.

Key words:
Childbirth; Cesarean section; Care; Epidemiology; Brazil