Considering the female preponderance of rheumatoid arthritis (RA), and disease onset typically after the reproductive years, pregnancy and childbirth may play a role in the aetiology of the disease. Adverse outcomes of pregnancy have been found to precede the diagnosis of autoimmune diseases, including RA, but the evidence is scant and inconsistent. Therefore, we investigate whether pregnancy loss is associated with the risk of RA in Chinese women. Data from the China Kadoorie Biobank, conducted by the University of Oxford and the Chinese Centre for Disease Control and Prevention, of 299,629 Chinese women who had been pregnant were used. Multivariable logistic regression and stratified analyses were employed to analyse the association between types of pregnancy loss with the risk of RA. Pregnancy loss was significantly associated with increased risk of RA (OR 1.12, 95% CI 1.06–1.18), specifically, spontaneous (OR 1.11, 95% CI 1.03–1.20) and induced abortions (OR 1.11, 95% CI 1.06–1.17). There was no significant association between stillbirth and the risk of RA (OR 1.07, 95% CI 0.97–1.18). The risk of developing RA increases with the number of pregnancy losses: one loss confers an OR of 1.09 (95% CI 1.03–1.16), two an OR of 1.13 (95% CI 1.05–1.20), three or more an OR of 1.19 (95% CI 1.10–1.28) and OR of 1.06 (95% CI 1.03–1.08) for each additional. Spontaneous and induced abortions are associated with an increased risk of RA in Chinese women.

BackgroundChronic obstructive pulmonary disease (COPD) is an inflammatory lung disease characterized by airflow blockage. Pregnancy and pregnancy loss may be related to an elevated risk of COPD, although studies have yet to report on this association. Hence, this study aims to investigate the association between pregnancy and pregnancy loss with the risk of COPD among Chinese women.MethodsData on 302,510 female participants from the China Kadoorie Biobank were utilized for this study. Multivariable logistic regression, stratified by sociodemographic and lifestyle factors, was employed to obtain the odds ratio (ORs) and 95% confidence intervals (CIs) for the association between pregnancy and pregnancy loss with COPD.ResultsPregnancy loss was significantly associated with increased risk of COPD (OR 1.19, 95% CI 1.13–1.25), specifically, spontaneous (OR 1.19, 95% CI 1.11–1.29) and induced abortion (OR 1.18, 95% CI 1.12–1.25). Stillbirth, however, was not significantly associated with the risk of COPD (OR 1.09, 95% CI 0.99–1.20). Increasing number of pregnancy losses was associated with increasing risk of COPD (one pregnancy loss: OR 1.14, 95% CI 1.07–1.21, two or more pregnancy loss: OR 1.25, 95% CI 1.17–1.32, and each additional pregnancy loss: OR 1.06, 95% CI 1.03–1.09). A single pregnancy was significantly associated with reduced risk of COPD (OR 0.75, 95% CI 0.59–0.97), although each additional pregnancy was significantly associated with increased risk of COPD (OR 1.03, 95% CI 1.01–1.04).ConclusionPregnancy loss, in particular, spontaneous and induced abortions are associated with increased risk of COPD among Chinese women. A single pregnancy, however, demonstrated protective effects.

Background While the association between pregnancy loss and individual cardiometabolic diseases (CMDs) is well-established, its impact on the risk of coexisting CMDs remains unclear. Therefore, the aim of this study is to investigate the association between pregnancy loss with the risk of cardiometabolic multimorbidity in Chinese women. Method Data of 299,582 female participants aged 30–79 years old from the China Kadoorie biobank were utilized. Cardiometabolic multimorbidity was defined as the coexistence of two or more CMDs, including coronary heart disease, stroke, hypertension, and diabetes. Multivariable logistic regression was used to evaluate the odds ratios (ORs) between the types of pregnancy loss with the risk of cardiometabolic multimorbidity, characterized by the number and type of CMD. Results After adjusting for confounding factors, pregnancy loss was found to be significantly associated with increased cardiometabolic multimorbidity risk (OR, 1.12 95% CI 1.07–1.17). Specifically, pregnancy loss due to spontaneous and/or induced abortion (OR 1.09, 95% CI 1.02–1.16 and OR 1.12, 95% CI 1.07–1.18, respectively). In contrast, no significant association was found between stillbirth and cardiometabolic multimorbidity (OR 1.01, 95% CI 0.93–1.09). The risk of cardiometabolic multimorbidity increases as the number of pregnancy loss increases (one pregnancy loss: OR 1.09, 95% CI 1.04–1.15, two or more pregnancy loss: OR 1.14, 95% CI 1.08–1.20). This increase was more apparent in older women. Similarly, the diagnosis of multiple CMDs increases with increasing number of pregnancy loss. Pregnancy loss was related to higher risk of cardiometabolic multimorbidity regardless of the CMD combinations, when compared with participants without any CMDs (p < 0.05). Conclusion Pregnancy loss, in particular, spontaneous and induced abortion was significantly associated with greater risk of cardiometabolic multimorbidity. The associations were stronger among those with recurrent pregnancy loss.