Abstract: Objective To examine the incidence and associated factors of unintended pregnancy among adolescent females within one year following receipt of post-abortion care (PAC) services, with a view to providing empirical evidence for strategies to reduce unintended pregnancy rates in this population. Furthermore, to explore the significance of multi-sectoral collaboration in adolescent sexuality education, and to provide reference points for policy formulation and implementation of targeted interventions. Methods Adolescent females who underwent induced abortion at Zhengzhou Maternal and Child Health Hospital between January 2020 and April 2023 were enrolled. All participants received individualized PAC services delivered in a one-to-one manner by designated nurses. A follow-up was conducted one year post-discharge to assess the incidence of unintended pregnancy. Descriptive statistics were used to analyze the incidence, and both univariate and multivariate analyses were performed to identify factors associated with the occurrence of unintended pregnancy. Results Of the 1 149 participants, 105 experienced an unintended pregnancy within one year, yielding an incidence rate of 9.14%. Cox regression analysis revealed that age (20-24 years, HR=0.201), contraceptive adherence (consistent use, HR=0.246), knowledge-behavior disparity (HR=2.498), unplanned sexual activity (HR=2.706), underestimation of pregnancy risk (HR=2.191), lack of perceived need for sexual education (HR=3.047), reliance on internet/television for sexual health information (HR=3.434), and irregular menstruation (HR=2.373) were significant correlates of unintended pregnancy one year post-intervention (all P<0.05). Conclusions Despite PAC provision, adolescent females exhibited a persistently high unintended pregnancy rate, underscoring the need for targeted interventions. Enhancing sexual education quality, improving contraceptive accessibility and adherence, and addressing knowledge-behavior disparities are critical to reducing unintended pregnancy incidence in this population.

Key words: Unintended pregnancy, Adolescent females, Post-abortion care services, Risk factors, Sexual education, Contraceptive services