Volume 30, Number 2, June 2004
In Brazil, Women Who Lack Knowledge About Fertility Control Are Those Most Likely to Become Sterilized
Brazilian women who have had three or more live births are significantly more likely than those of lower parity to be sterilized and are significantly less likely to know of four or more contraceptive methods, according to a cross-sectional survey of women aged 30-49 in Sao Paulo state.1 They also began childbearing earlier and have a lower monthly income than women with fewer children. Taken together, the researchers suggest, these findings suggest that Brazil's high sterilization rate may reflect, in part, high fertility in a group of women who initiate childbearing early in life and lack the knowledge to plan and control their fertility.
To identify factors that contribute to high use of sterilization among Brazilian women—50% of those aged 35 and older in 1996 had been sterilized—researchers obtained information on social and demographic characteristics and reproductive history from a random sample of women aged 30-49 in Campinas, Sao Paulo state, in 1996. For the analysis, 236 women who had been sterilized for at least five years were matched to 236 nonsterilized women of similar age (within two years) who lived in the same census tract.
Bivariate analyses found significant differences between sterilized and nonsterilized women in marital status, duration of marriage (or cohabitation), and age at cohabitation. A greater proportion of sterilized woman than of nonsterilized women were married (76% vs. 59%) and had lived with a partner or spouse for 20 years or more (42% vs. 28%). Thirty-four percent of sterilized women had begun cohabiting at age 19 or younger, compared with 18% of nonsterilized women. Sterilized women also had a significantly greater number of pregnancies and live births than nonsterilized women. Seventy-six percent of sterilized women had had three or more pregnancies, and 69% had had at least three live births, compared with 33% and 24%, respectively, of nonsterilized women. Women who had been sterilized were more likely than those who had not to have had their first birth at age 19 or younger (36% vs. 21%). There was no significant difference between the two groups of women in the number of abortions they had, or their age at delivery of their youngest child (mean, 28 years in each group).
Because of the strong association between sterilization and high parity, the researchers performed a logistic regression analysis to determine predictors of having had three or more births. This analysis excluded 114 women for whom data were missing for one or more values. The odds of high parity were elevated for sterilized women (odds ratio, 7.0) and decreased for women familiar with four or more contraceptive methods (0.4). The older a woman was at the time of her first birth, the lower her odds were of having had three or more live births (0.8). However, the odds rose with the woman's age at interview (1.1). Women with a per capita monthly income greater than US$300 were significantly less likely to have had three or more live births than were those with a lower income (0.5).
While Brazil's high sterilization rate is thought to play a role in the country's rapidly declining fertility rate, the researchers say their findings suggest that the decline is due in part to nonsterilized women controlling their fertility and having fewer children than sterilized women. According to the researchers, adequate counseling on sexual and reproductive health should begin in early adolescence, when women are making life and reproductive choices. They conclude that "in order to reduce the number of young women who choose surgical sterilization over equally effective, but reversible methods, it is necessary to act early in life."
1. Osis MJD et al., Fertility and reproductive history of sterilized and non-sterilized women in Campinas, Sao Paulo, Brazil, Cad. Saúde Pública, 2003, 19(5):1399-1404.