The Relationship Between Retrospectively Measured Pregnancy Intentions and Women’s Stages of Behavior Change for Contraceptive Use and Effectiveness Level of Contraceptive Method Choice

<b>Background/Objectives</b>: Unintended pregnancy is linked to an increased risk of subsequent unintended pregnancies, but its impact on contraceptive use and intention remains vastly understudied. This study assessed whether unintended pregnancy independently influences women's stages of behavior change for contraceptive use and the effectiveness of their chosen contraceptive methods. <b>Methods</b>: Using pooled data from three cross-sectional surveys of the Performance Monitoring and Accountability 2020 project in Nigeria, we analyzed responses from 8014 non-pregnant women aged 15-49 years nested within 892 communities. Multilevel multinomial logistic regression accounted for compositional and contextual factors. <b>Results</b>: Women with a mistimed pregnancy had higher odds of being in the contemplation stage of behavior change compared to those with an intended pregnancy (adjusted odds ratio [aOR] = 1.59, 95% confidence interval [CI] = 1.13-2.22), with a similar but non-significant trend for unwanted pregnancies (aOR = 1.46, 95% CI = 0.91-2.34). Mistimed and unwanted pregnancies were also linked to higher odds of being in the action stage (aOR = 2.17 and 1.85, respectively). Regarding contraceptive effectiveness, women with a mistimed pregnancy were more likely to use moderately effective methods (aOR = 1.47, 95% CI = 1.02-2.12) and highly effective methods (aOR = 2.45, 95% CI = 1.41-4.26). Unwanted pregnancies showed even stronger associations with highly effective methods (aOR = 4.03, 95% CI = 1.18-13.74). Community-level variability significantly influenced outcomes. <b>Conclusions</b>: Together, these findings underscore the importance of person-centered approaches and public health interventions tailored to stages of contraceptive behavior change, targeting both women and communities at high risk of unintended pregnancy.