Association of spontaneous abortion with all cause and cause specific premature mortality: prospective cohort study

• Type of Material: Article
• Authors: Yi-Xin Wang, Brigham and Women’s Hospital and Harvard Medical School; Lidia Minguez-Alarcon, Brigham and Women’s Hospital and Harvard Medical School; Audrey Gaskins, Emory University; Stacey A Missmer, Michigan State University; Janet W Rich-Edwards, Harvard Medical School; JoAnn E Manson, Brigham and Women’s Hospital and Harvard Medical School; An Pan, Huazhong University of Science & Technology; Jorge E Chavarro, Harvard T H Chan School of Public Health
• Language: English
• Date: 2021-03-24
• Publisher: BMJ PUBLISHING GROUP
• Publication Version: Final Published Version
• Copyright Statement: © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
• License: Creative Commons Attribution-NonCommercial 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1136/bmj.n530
• Title of Journal or Parent Work: BMJ-BRITISH MEDICAL JOURNAL
• Volume: 372
• Start Page: n530
• End Page: n530
• Grant/Funding Information: This study was supported by grants U01-HL145386, U01-CA176726, R01-HL034594, and R01-HL088521 from the National Institutes of Health. The funders had no role in considering the study design or in the collection, analysis, interpretation of data, writing of the report, or decision to submit the article for publication.
• Keywords: Science & Technology; REPRODUCTIVE HISTORY; ISCHEMIC-HEART-DISEASE; Medicine, General & Internal; STROKE; General & Internal Medicine; WOMEN; Life Sciences & Biomedicine; SUSTAINABLE DEVELOPMENT GOAL; CARDIOVASCULAR-DISEASE; HEALTH; RISK; MISCARRIAGE; RECURRENT PREGNANCY LOSS
• Research Categories: Health Sciences, Epidemiology; Health Sciences, Nutrition; Health Sciences, Obstetrics and Gynecology

Abstract

Objective To investigate the association of spontaneous abortion with the risk of all cause and cause specific premature mortality (death before the age of 70). Design Prospective cohort study. Setting The Nurses' Health Study II (1993-2017), United States. Participants 101 681 ever gravid female nurses participating in the Nurses' Health Study II. Main outcomes measures Lifetime occurrence of spontaneous abortion in pregnancies lasting less than 6 months, determined by biennial questionnaires. Hazard ratios and 95% confidence intervals for all cause and cause specific premature death according to the occurrence of spontaneous abortion, estimated with time dependent Cox proportional hazards models. Results During 24 years of follow-up, 2936 premature deaths were recorded, including 1346 deaths from cancer and 269 from cardiovascular disease. Crude all cause mortality rates were comparable for women with and without a history of spontaneous abortion (1.24 per 1000 person years in both groups) but were higher for women experiencing three or more spontaneous abortions (1.47 per 1000 person years) and for women reporting their first spontaneous abortion before the age of 24 (1.69 per 1000 person years). The corresponding age adjusted hazard ratios for all cause premature death during follow-up were 1.02 (95% confidence interval 0.94 to 1.11), 1.39 (1.03 to 1.86), and 1.27 (1.11 to 1.46), respectively. After adjusting for confounding factors and updated dietary and lifestyle factors, the occurrence of spontaneous abortion was associated with a hazard ratio of 1.19 (95% confidence interval 1.08 to 1.30) for premature mortality during follow-up. The association was stronger for recurrent spontaneous abortions (hazard ratio 1.59, 95% confidence interval 1.17 to 2.15 for three or more spontaneous abortions; 1.23, 1.00 to 1.50 for two; and 1.16, 1.05 to 1.28 for one compared with none), and for spontaneous abortions occurring early in a woman's reproductive life (1.32, 1.14 to 1.53 for age ≤23; 1.16, 1.01 to 1.33 for ages 24-29; and 1.12, 0.98 to 1.28 for age ≥30 compared with none). When cause specific mortality was evaluated, the association of spontaneous abortion with premature death was strongest for deaths from cardiovascular disease (1.48, 1.09 to 1.99). Spontaneous abortion was not related to premature death from cancer (1.08, 0.94 to 1.24). Conclusions Spontaneous abortion was associated with an increased risk of premature mortality, particularly death from cardiovascular disease.