SOMANZ Oral Presentation Australasian Diabetes in Pregnancy Society and Society of Obstetric Medicine Australia and New Zealand Joint Scientific Meeting 2025

Incidence, trends and risk factors for VTE during pregnancy and postpartum: a population-based study (128401)

CHENXI Li 1 2 , Giselle Kidson-Gerber 3 4 , Laura Gerhardy 1 2 5 , Natasha Nassar 1 2 6 , Antonia Shand 1 2 3
  1. Leeder Centre for Health Policy, Economics and Data, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
  2. Child Population and Translational Health Research, Children’s Hospital at Westmead Clinical School, Faculty of Medicine and Health, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
  3. Royal Hospital for Women, Randwick, NSW, Australia
  4. Prince of Wales Hospital, Randwick, NSW, Australia
  5. Nepean Hospital,, Kingswood, NSW, Australia
  6. Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia

Background

Venous thromboembolism (VTE) including Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) is a leading cause of maternal morbidity and mortality. We aimed to assess incidence, trends, and risk factors for VTE during pregnancy and postpartum in New South Wales (NSW), Australia.

Methods

A population-based cohort study was conducted using linked NSW administrative birth, hospital admission and death records from 2003-2018. VTE was identified using ICD10-AM codes and classified by VTE type (DVT-only, PE-only, combined-DVT/PE) and timing (first VTE during pregnancy, birth admission, ≤6-weeks postpartum). Overall and annual incidence of VTE was calculated and multivariable logistic regression models were used to assess association between risk factors and timing of VTE.   

Results

Of 1,518,278 pregnancies, 3,052 VTE cases (2.01/1,000 pregnancies) were recorded. From 2003-2018, incidence of overall VTE remained stable, but DVT-only decreased from 1.99 to 1.13/1000, whereas PE-only and combined DVT/PE cases increased from 0.14 to 0.41 and 0.07 to 0.54/1000, respectively.  VTE incidence was highest during pregnancy (0.8/1000) compared to birth admission (0.70/1000) and postpartum(0.52/1000). Women with pre-existing medical conditions, including history of VTE had a higher risk of pregnancy VTE. While, women with preeclampsia, preterm birth, caesarean section and postpartum hemorrhage had increased risk of VTE during birth admission and postpartum.

Conclusion

Despite prevention initiatives, VTE rates are higher than reported in other studies. VTE rates haven't changed and PE rates have risen over time. This may reflect increased awareness, testing, earlier diagnosis and/or increased risk factors. Improved identification of risk factors and management are required.