Premature mortality after pregnancy loss: Trends at 1, 5, 10 years, and beyond

Little is known on the long-term risk of mortality following pregnancy loss. We assessed risks of premature mortality up to three decades after miscarriage, induced abortion, ectopic or molar pregnancy, and stillbirth relative to live birth.

We carried out a longitudinal cohort study of 1,293,640 pregnant women with 18,896,737 person-years of follow-up in Quebec, Canada, from 1989 to 2018. We followed the women up to 29 years after their last pregnancy event to determine the time and cause of future in-hospital deaths before age 75 years. We used adjusted Cox regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association of miscarriage, induced abortion, ectopic pregnancy, molar pregnancy, and stillbirth with premature mortality, compared with live birth.

Premature mortality rates were higher for most types of pregnancy loss than live birth. Compared with live birth, pregnancy loss was associated with an elevated risk of premature mortality (HR_miscarriage 1.48, 95% CI 1.33, 1.65; HR_{induced abortion} 1.50, 95% CI 1.39, 1.62; HR_ectopic 1.55, 95% CI 1.35, 1.79; and HR_stillbirth 1.68, 95%. CI 1.17, 2.41). Molar pregnancy was not associated with premature mortality (HR 0.87, 95% CI 0.33, 2.32). Miscarriage and induced abortion were associated with most causes of death, whereas ectopic pregnancy was associated with cardiovascular (HR 2.18, 95 % CI 1.39, 3.42), cancer (HR 1.38, 95 % CI 1.11, 1.73), and suicide-related mortality (HR 4.94, 95 % CI 2.29, 10.68). Stillbirth was associated with cardiovascular mortality (HR 4.91, 95 % CI 2.33, 10.36).

Pregnancy loss is associated with an elevated risk of premature mortality up to three decades later, particularly cardiovascular, cancer, and suicide-related deaths.