Use of modern contraceptive methods and pregnancy planning: a cohort study.

To investigate the association between unplanned pregnancy and use of modern contraceptive methods at 3-, 12-, and 24-months postpartum using an intersectional approach for examining inequalities, in the 2015 Pelotas birth cohort, Brazil.

We evaluated the use of modern contraceptives after delivery, comparing women who had planned and unplanned pregnancies in 2015. The number of women included in this study was: 4,021, 3,687, and 3,558, at 3-, 12-, and 24-month postpartum follow-ups, respectively. Analyses were restricted to women who needed contraception by the time of each postpartum follow-up interview. Sociodemographic indicators were also investigated. Descriptive (absolute and relative frequencies), bivariate, and multivariate statistical analyses were conducted. These analyses included the main exposure and the sociodemographic variables. In the three follow-up interviews, double stratification was used to investigate for intersectionalities between pregnancy planning and family income, and pregnancy planning and living with partner.

Women who had unplanned pregnancies presented the lowest use of modern contraceptives. A negative association between unplanned pregnancy and use of modern contraception was found at 3- (PR = 0.97, 95%CI: 0.95-0.99) and 24-months postpartum (PR = 0.96, 95%CI: 0.94-0.98). In general, women who did not live with a partner, with lower schooling level, and who were 35 or older presented lower use of modern contraception. Women who had unplanned pregnancies with lower family income and who did not live with a partner presented a lower prevalence of modern contraceptive use.

Despite the possible benefits of the use of modern contraception in the postpartum period, women who had unplanned pregnancies presented the lowest prevalence. No consistent pattern was identified for this association over time. It is necessary to consider important sociodemographic factors such as living with partner as well as possible pathways to reduce inequalities.