Incidence, risk factors and outcome of venous thromboembolism in critically ill obstetric patients

Introduction

Venous thromboembolism (VTE) during pregnancy remains a significant cause of obstetric morbidity and mortality, presenting the leading cause of maternal mortality in the USA and Europe. In the present study we tried to determine the prevalence of VTE, risk factors and mortality associated with VTE in critically ill obstetric patients.

Methods

A retrospective analysis of data collected prospectively. Charts were reviewed for maternal characteristics of age, parity, body mass index (BMI), presenting clinical symptoms and signs, biological disturbances (deficiencies of protein S, protein C, antithrombin III, etc.), obstetric management modalities and diagnosis of ICU admission. Objective modalities used to diagnose VTE included Doppler ultrasound, computed tomography, and magnetic resonance imaging scanning. High-probability ventilation and perfusion scans were considered confirmatory of pulmonary embolism, patients with low or intermediate probability scans had pulmonary angiography for confirmation. SAPS Obst and APACHE III scores were collected. The main outcome of interest was the vital status at ICU discharge.

Results

From January 1996 to July 2004, 541 obstetrics patients were hospitalized in our ICU; 31 presented venous thromboembolism (5.73%), 27 of them in the postpartum period (87%). The mean age was 28.7 ± 6.2 (20–40) years, mean gravidity was 2.5 ± 1.5 (1–8), mean parity was 1.97 ± 1.27 (0–5) and BMI was >27 in 17 cases. One patient presents a history of intracranial venous thrombosis, another one with a history of ischemic stroke and a third with Behçet disease. Two patients had haematological abnormalities (deficiencies of protein C, antiphospholipid antibodies). Delivery was vaginal in 15 cases and caesarean in 16 cases (P = 0.025). Two patients had deep-vein thrombosis (6.45%), 15 with pulmonary embolism (48.3) and 14 with intracranial venous thrombosis (45.1). The APACHE III score was 19.4 ± 13.8 and SAPS Obst was 13 ± 6. Five deaths (16.1%) occurred in this study and three patients left the hospital with neurologic deficits, requiring chronic care or rehabilitation.

Conclusion

We found that vaginal delivery is a risk factor for thromboembolic events in pregnancy. This indicates that we need to review our antithrombotic strategy for preventing VTE events in pregnancy for this mode of delivery.