Importance Women who experience imprisonment have high morbidity and an increased risk of adverse pregnancy outcomes. Antenatal care could modify pregnancy-related risks, but there is a lack of evidence regarding antenatal care in this population. Objectives To examine antenatal care quality indicators for women who experience imprisonment and to compare these data with data for the general population. Design, Setting, and Participants This population-based, retrospective cohort study used linked correctional and health administrative data from women released from provincial prison in Ontario, Canada, in 2010 and women in the general population with deliveries at 20 weeks' gestation or greater from January 1, 2005, to December 31, 2015. Data analysis was performed from January 1, 2017, to May 4, 2020. Exposures Pregnancies in women with time in prison during pregnancy (prison pregnancies), pregnancies in women with time in prison but not while pregnant (prison control pregnancies), and pregnancies in women in the general population (general population pregnancies). Main Outcomes and Measures Antenatal care quality indicators: first-trimester visit, first-trimester ultrasonography, and 8 or more antenatal care visits. Results A total of 626 prison pregnancies in 529 women (mean [SD] age, 26.6 [5.4] years), 2327 prison control pregnancies in 1570 women (mean [SD] age, 26.2 [5.4] years), and 1 & x202f;308 & x202f;879 general population pregnancies in 884 & x202f;063 women (mean [SD] age, 30.3 [5.3] years) were studied. Of 626 prison pregnancies, 193 women (30.8%; 95% CI, 27.1%-34.6%) had a first-trimester visit, 272 (48.4%; 95% CI, 44.4%-52.4%) had at least 8 antenatal care visits, and 209 (34.6%; 95% CI, 31.0%-38.4%) received first-trimester ultrasonography. In 2327 prison control pregnancies, 1106 women (47.5%; 95% CI, 45.3%-49.8%) had a first-trimester visit, 1356 (59.2%; 95% CI, 56.9%-61.4%) had 8 or more antenatal care visits, and 893 (38.5%; 95% CI, 36.4%-40.6%) received first-trimester ultrasonography. Compared with 1 & x202f;308 & x202f;879 general population pregnancies, the odds of antenatal care were lower for the first-trimester visit (odds ratios [ORs], 0.11 [95% CI, 0.09-0.13] in prison pregnancies and 0.23 [95% CI, 0.21-0.25] in prison control pregnancies), 8 or more antenatal care visits (ORs, 0.16 [95% CI, 0.14-0.19] in prison pregnancies and 0.25 [95% CI, 0.23-0.28] in prison control pregnancies), and first-trimester ultrasonography (ORs, 0.43 [95% CI, 0.36-0.50] in prison pregnancies and 0.51 [95% CI, 0.46-0.55] in prison control pregnancies). Conclusions and Relevance This study found that women who experienced imprisonment were substantially less likely to receive adequate antenatal care than were women in the general population whether or not they were in prison during pregnancy. Efforts are needed to improve antenatal care for this population both in prison and in the community. his cohort study examines antenatal care quality indicators for women who experience imprisonment compared with women in the general population in Ontario, Canada. Question Do women who experience imprisonment in Ontario, Canada, have adequate antenatal care? Findings In this cohort study of 626 pregnancies during time in prison and 2327 pregnancies in women with time in prison but not while pregnant, of the women who experienced imprisonment during pregnancy, 30.8% had a first-trimester visit, 48.4% had 8 or more antenatal care visits, and 34.5% received ultrasonography in their first trimester. Of the women who experienced imprisonment but not during pregnancy, 47.5% had a first trimester visit, 59.2% had 8 or more antenatal care visits, and 38.5% received ultrasonography in their first trimester. Meaning The findings suggest that the odds of receiving antenatal care are lower for women who have experienced imprisonment than for the general population and that further research and interventions are needed to improve antenatal care in women who experience imprisonment.
