The prevalence of and factors associated with prior induced abortion among women who gave birth in Victoria, 2010–2019

Abstract Objective To assess the prevalence of a history of induced abortion among women who gave birth in Victoria during 2010–2019; to assess the association of socio‐demographic factors with a history of induced abortion. Study design Retrospective cohort study; analysis of cross‐sectional perinatal data in the Victorian Perinatal Data Collection (VPDC). Setting, participants All women who gave birth (live or stillborn) in Victoria, 1 January 2010 – 31 December 2019. Main outcome measures Self‐reported induced abortions prior to the index birth; outcome of the most recent pregnancy preceding the index pregnancy. Results Of the 766 488 women who gave birth during 2010–2019, 93 251 reported induced abortions (12.2%), including 36 938 of 338 547 nulliparous women (10.9%). Women living in inner regional (adjusted odds ratio [aOR], 0.94; 95% confidence interval [CI], 0.93–0.96) or outer regional/remote/very remote areas (aOR, 0.86; 95% CI, 0.83–0.89) were less likely than women in major cities to report induced abortions. The likelihood increased steadily with age at the index birth and with parity, and was also higher for women without partners at the index birth (aOR, 2.20; 95% CI, 2.16–2.25) and Aboriginal and Torres Strait Islander women (aOR, 1.32; 95% CI, 1.25–1.40). The likelihood was lower for women born in most areas outside Australia than for those born in Australia. The likelihood of a history of induced abortion declined across the study period overall (2019 v 2010: 0.93; 95% CI, 0.90–0.96) and for women in major cities (0.88; 95% CI, 0.84–0.91); rises in inner regional and outer regional/remote/very remote areas were not statistically significant. Conclusions Access to abortion care in Victoria improved during 2010–2019, but the complex interplay between contraceptive use, unintended pregnancy, and induced abortion requires further exploration by remoteness of residence. Robust information about numbers of unintended pregnancies and access to reproductive health services are needed to guide national sexual and reproductive health policy and practice.