Sociodemographic and reproductive characteristics of pregnant women with unplanned pregnancy residing in the state of São Paulo, Brazil: a cross-sectional study

The aim of our study was to assess the associated factors of planned and unplanned pregnancies (UPs) among pregnant women in São Paulo, Brazil. We conducted a cross-sectional study from March 2023 to June 2024 and invited pregnant women aged 18 to 49 years. We used the Brazilian-validated version of the London Measure of Unplanned Pregnancy to assess pregnancy intentions. We estimated absolute and relative frequencies of planned and UPs by sociodemographic and reproductive characteristics. Bivariate and multiple regression analysis were performed to evaluate the associated factors for UPs. We included 534 participants; 65.7% reported an UP. Black or Biracial vs White women (74% vs. 57%, <i>p</i> &lt; 0.001), with 0 to 9 years vs. those with &gt;9 of schooling (77% vs. 51%, <i>p</i> &lt; 0.001), and single vs married women (85% vs. 48%, <i>p</i> &lt; 0.001) were associated with UPs. Parous women or those reporting a younger age at their sexual debut were more commonly reported UPs. The associated factors to UPs were being Black or Biracial (Odds ratio [OR] 1.68, 95% Confidence Interval [CI] 1.11;2.57), reporting fewer schooling years (OR 1.61, 95% CI 1.01;2.54), not being married [(OR 2.41, 95% CI 1.53;3.84) for cohabiters and OR 5.23, 95% CI 2.93;9.74) for single] and reporting additional births (OR 1.28, 95% CI 1.07;1.56). Black or Biracial, with fewer years of schooling, not married, and parous women were at a higher risk of UPs. These women tend to face structural barriers to planning the size and timing of their families, requiring actions like increasing tertiary education access and guaranteeing universal modern contraceptive availability to leverage these disadvantages and fulfil their sexual and reproductive rights. In São Paulo, Black or Biracial, less educated, not married, and parous women still face challenges in deciding the timing and size of their families.