Short Attention Span Summary
What do we learn from this study?
We know pregnancy and the postpartum period is a hypercoagulable state, but how does a vaginal delivery compare with c-section for venous thromboembolism (VTE) risk? This was a meta-analysis of primarily retrospective studies that found the risk of VTE was about 4 times greater after a c-section than a vaginal delivery. Overall VTE risk was 3/1000 after c-section.
Why does this matter?
Because we often see postpartum patients in the ED (when they don’t disappear to L&D). The mode of delivery makes a difference in the risk for postpartum PE. Surgical delivery puts the mother at greater risk of PE, so our suspicion for it has to be higher after a c-section. We don’t want new moms to die of a PE on our watch.
Want more help?
The next time you have a pregnant patient present with suspected PE, wouldn’t it be nice if Jeff Kline (of PERC rule fame) could personally walk you through the workup? He does in the Evidence Care free clinical decision support tool. It’s pretty cool. Yes, I am a nerd.
Chest. 2016 Jun 1. pii: S0012-3692(16)49108-7. doi: 10.1016/j.chest.2016.05.021. [Epub ahead of print]
1Division of Angiology and Hemostasis, Department of Specialties of Medicine, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland; Seattle Epidemiologic Research and Information Center, Department of Veterans Affairs Office of Research and Development, Seattle, USA. Electronic address: firstname.lastname@example.org.
2Division of Angiology and Hemostasis, Department of Specialties of Medicine, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
3Department of Obstetrics and Gynecology and of Maternal Fetal Medicine, University of Wisconsin, Madison, USA; Department of Obstetrics and Gynecology, University of Washington, Seattle, USA.
4Seattle Epidemiologic Research and Information Center, Department of Veterans Affairs Office of Research and Development, Seattle, USA; Department of Epidemiology, University of Washington, Seattle, USA.
Cesarean sections (CS) are believed to be associated with greater risks of postpartum venous thromboembolism (VTE). Our objective was to systematically review the evidence on this association and on the absolute risk of VTE after CS.
We searched Pubmed, Embase and conference proceedings from 1980 to 11/2015 for reports on the associations of delivery methods with postpartum VTE and on the incidence of VTE after CS. We excluded studies on thrombophilia or recurrent VTE and restricted to prospective studies when assessing the incidence of VTE. Pooled relative and absolute risks were estimated with random-effects models.
Our search retrieved 28 mostly retrospective observational studies comparing risks of VTE after CS and after vaginal deliveries (VD) (n>53000 VTE events), and 32 prospective studies reporting risks of VTE after CS (n=218 VTE events). Compared with VD, the relative risk of VTE after CS ranged from 1-22, with a meta-analytic odds ratio (OR) of 3.7 (95%CI 3.0-4.6). Adjustment for age and BMI had a marginal influence on the estimated pooled OR. Associations were observed for both elective and emergency CS, with stronger estimates of associations for emergency CS. The pooled incidence was 2.6VTE/1000 CS (95%CI 1.7-3.5), and was greater in studies with a longer and better follow-up in the postpartum (4.3/1000 CS).
The risk of VTE is 4-fold greater after CS than VD, appears independent of other VTE risk factors, and is greater after emergency than elective CS. On average, 3 in 1000 women will develop a VTE after CS.
Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.
PMID: 27262227 [PubMed – as supplied by publisher]