Cancer in pregnancy increases the risk of venous thromboembolism: a nationwide cohort study.

OBJECTIVE: To investigate if cancer in pregnancy causes a higher risk of venous thromboembolism (VTE) during pregnancy and postpartum compared with pregnant women without cancer. DESIGN: A historical prospective cohort study using data from nationwide registries. SETTING AND POPULATION: We assessed all pregnancies in Denmark between 1 January 1977 and 31 December 2017. METHODS: We linked information concerning cancer diagnosis, pregnancy and VTE diagnosis and potential confounders. Event rates of VTE for women with pre-pregnancy cancer, cancer in pregnancy and without cancer were calculated per 10 000 pregnancies and compared using logistic regression analysis. MAIN OUTCOME MEASURES: Occurrence of VTE during pregnancy or the postpartum period. RESULTS: A total of 3 581 214 pregnancies were included in the study and we found 1330 women with cancer in pregnancy. In pregnant women with cancer, the event rate of VTE was 75.2 per 10 000 pregnancies compared with 10.7 per 10 000 pregnancies in the no cancer group. The findings correspond to an increased adjusted odds ratio of 6.50 (95% CI3.5-12.1) in the cancer in pregnancy group in comparison with the no cancer group. CONCLUSIONS: Women with cancer in pregnancy have a markedly higher risk of pregnancy-associated VTE compared with women without cancer. In pregnancy-related VTE risk assessment, the presence of cancer alone may be sufficient to indicate thromboprophylaxis. TWEETABLE ABSTRACT: Cancer in pregnancy increases the risk of VTE during pregnancy and the postpartum period.

Female sex as a risk factor for stroke in atrial fibrillation: a nationwide cohort study.

BACKGROUND: Female sex has been suggested as a risk factor for stroke/thromboembolism in patients with non-valvular atrial fibrillation (AF) and has therefore been included within risk scores, e.g., the CHA2 DS2 -VASc score, and guidelines. OBJECTIVES: To investigate the risk of stroke/thromboembolism associated with female sex in non-valvular AF patients. PATIENTS/METHODS: Using the national Danish registers, we identified non-anticoagulated patients discharged with non-valvular AF (1997-2008), and subdivided the population into three age intervals: < 65, 65-74 and ≥ 75 years. We calculated stroke rates according to sex, and assessed the stroke risk associated with female sex by using Cox regression analysis. RESULTS: We included 87,202 AF patients, and 44,744 (51.3%) were female. The rate of stroke/thromboembolism for females aged < 65 and 65-74 years was not increased as compared with men, whereas the rate for females aged ≥ 75 years was increased. At both 1-year and 12-year follow-up, female sex did not increase the risk of stroke for patients aged < 75 years. At 1-year follow-up, the hazard ratios associated with female sex were 0.89 (95% confidence interval [CI] 0.70-1.13) and 0.91 (95 CI 0.79-1.05) for patients aged < 65 and 65-74 years, respectively, and being female and aged ≥ 75 years was associated with an increased risk of stroke of 1.20 (95 CI 1.12-1.28). CONCLUSION: Female sex was only associated with an increased risk of stroke for AF patients aged ≥ 75 years. Our study suggests that female sex should not be automatically included as an independent stroke/thromboembolic risk factor in guidelines or in the CHA2 DS2 -VASc score, without careful prior consideration of the 'age < 65 and lone AF' criterion.