Background: Women with only pregnancy terminations or only miscarriages have an increased mortality risk. We investigated the association between vaginal bleeding (VB) in pregnancy ending in childbirth and women's mortality. Methods: We conducted a cohort study in Denmark, which included 1,354,181 women and their 3,162,317 pregnancies (1979-2017) followed through 2018. We ascertained 70,835 VB-affected pregnancies and comparators: 2,236,359 VB-unaffected pregnancies ending in childbirth; 589,697 terminations; and 265,940 miscarriages. We computed all-cause and cause-specific mortality rates per 10,000 person-years (PY) and hazard ratios (HRs) with 95% confidence intervals (CIs) using Cox proportional hazards regression adjusted for age, calendar year, preexisting conditions, and socioeconomic factors. Results: There were 2,320 deaths from any cause among women following VB-affected pregnancy (mortality rate: 15.2, 95% CI: 14.6-15.9 per 10,000 PY); 55,030 deaths following VB-unaffected pregnancy (12.7, 12.6-1.28); 27,500 deaths following a termination (21.9, 21.6-22.1), and 10,865 deaths following a miscarriage (19.2, 18.8-19.6). For comparison of VB-affected vs VB-unaffected pregnancies, associations with all-cause (HR: 1.14, 95% CI: 1.09-1.19), natural-causes (HR: 1.15, 95% CI: 1.09-1.22) and non-natural causes (HR: 1.27, 95% CI: 1.08-1.48) mortality attenuated in a sensitivity analysis of pregnancies recorded in 1994-2017 (HR: 1.00, 95% CI: 0.90-1.12, HR: 0.98, 95% CI: 0.85-1.14, and HR: 1.04, 95% CI: 0.71-1.51, respectively). Contrasts with remaining comparators did not suggest increased risks of all-cause, natural, or non-natural mortality causes. Conclusions: We found no evidence of an increased risk of mortality in women following VB-affected vs VB-unaffected pregnancy, termination, or miscarriage.

The authors have declared no competing interest.

No external funding was received for this study.

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Data used in this study were centrally pseudonymized at the servers of Statistics Denmark. According to Danish legislation, ethical permission is not required for registry-based research. This study was conducted according to Danish legislation, which does not require individuals' consent or ethical approval for registry-based research. This study was reported to the Danish Data Protection Agency and registered at Aarhus University with project nr. 2016-051-000001, sequential number 605.

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Individual-level data used in this study are not publicly available in accordance with Danish legislation.