@article { , title = {Impact of risk factors on the timing of first postpartum venous thromboembolism: a population-based cohort study from England}, abstract = {For women with preeclampsia, BMI \>30 kg/m2, infection, or those having cesarean delivery, VTE risk remained elevated for 6 weeks postpartum.For women with postpartum hemorrhage or preterm birth, the relative rate of VTE was only increased for the first 3 weeks postpartum.Impact on the timing of first postpartum venous thromboembolism (VTE) for women with specific risk factors is of crucial importance when planning the duration of thromboprophylaxis regimen. We observed this using a large linked primary and secondary care database containing 222?334 pregnancies resulting in live and stillbirth births between 1997 and 2010. We assessed the impact of risk factors on the timing of postpartum VTE in term of absolute rates (ARs) and incidence rate ratios (IRRs) using a Poisson regression model. Women with preeclampsia/eclampsia and postpartum acute systemic infection had the highest risk of VTE during the first 3 weeks postpartum (ARs ?2263/100?000 person-years; IRR ?2.5) and at 4-6 weeks postpartum (AR ?1360; IRR ?3.5). Women with body mass index (BMI) \>30 kg/m2 or those having cesarean delivery also had elevated rates up to 6 weeks (AR ?1425 at 1-3 weeks and ?722 at 4-6 weeks). Women with postpartum hemorrhage or preterm birth, had significantly increased VTE rates only in the first 3 weeks (AR ?1736; IRR ?2). Our findings suggest that the duration of the increased VTE risk after childbirth varies based on the type of risk factors and can extend up to the first 3 to 6 weeks postpartum.}, doi = {10.1182/blood-2014-05-572834}, eissn = {1528-0020}, issn = {0006-4971}, issue = {18}, journal = {Blood}, publicationstatus = {Published}, publisher = {American Society of Hematology}, url = {https://nottingham-repository.worktribe.com/output/733807}, volume = {124}, author = {Abdul Sultan, Alyshah and Grainge, Matthew J. and West, Joe and Fleming, Kate M. and Nelson-Piercy, Catherine and Tata, Laila J.} }