title: Impact of risk factors on the timing of first postpartum venous thromboembolism: a population-based cohort study from England.
abstract: 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/m(2) 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.
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, City Hospital, Nottingham, United Kingdom; and.
authors.forename: Alyshah
authors.initials: A
authors.lastname: Abdul Sultan
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, City Hospital, Nottingham, United Kingdom; and.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Grainge
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, City Hospital, Nottingham, United Kingdom; and.
authors.forename: Joe
authors.initials: J
authors.lastname: West
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, City Hospital, Nottingham, United Kingdom; and.
authors.forename: Kate M
authors.initials: KM
authors.lastname: Fleming
authors.affiliation: Women's Health Academic Centre, Guy's & St. Thomas' Foundation Trust, St. Thomas' Hospital, London, United Kingdom.
authors.forename: Catherine
authors.initials: C
authors.lastname: Nelson-Piercy
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, City Hospital, Nottingham, United Kingdom; and.
authors.forename: Laila J
authors.initials: LJ
authors.lastname: Tata
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D015999:Multivariate Analysis; D061366:Numbers Needed To Treat; D049590:Postpartum Period / Q000097:blood*; D011247:Pregnancy; D012307:Risk Factors; D013997:Time Factors; D054556:Venous Thromboembolism / Q000453:epidemiology*; D055815:Young Adult