PS1579 AN EPIDEMIOLOGIC STUDY OF PREGNANCY RELATED VENOUS THROMBO‐EMBOLISM IN SOUTH AFRICA: ARE HIV INFECTED WOMEN A NEW HIGH‐RISK GROUP?

Abstract

Background:Venous thrombo‐embolism (VTE) is an important cause of preventable morbidity and mortality in pregnancy. While much consideration has been given to inherited thrombophilias and a past history of VTE, epidemiologic studies to date have not examined the significance of human immunodeficiency virus (HIV) as a potential risk factor for pregnancy and postpartum related VTE. In South Africa this is of particular concern, considering that approximately one‐third of women attending antenatal clinics are HIV infected.Aims:A study was therefore performed at a single academic centre to investigate the clinical spectrum, incidence and risk factors for VTE in pregnancy and the puerperium in a population of Black South African women in order to guide evidence‐based thromboprophylaxis.Methods:A case control study of first time VTE during pregnancy or within 42 days postpartum was conducted between January and December 2018. A control group (n = 295) matched for population affinity and gestation were recruited. The medical records were reviewed for 30 baseline antepartum and/or postpartum risk factors for VTE. Statistical comparisons were performed using Fisher's exact test with calculation of odds ratios (OR) and 95% confidence intervals (CI). The study was approved by the Human Research Ethics Committee of the University of the Witwatersrand (M181018).Results:59 patients with the diagnosis of VTE in pregnancy or the puerperium were identified during the study period (34 with deep vein thrombosis, 23 with pulmonary embolus and two with both). The total number of deliveries during the study period was 8 361, giving an incidence of 4.4 per 1000 deliveries. In the multivariate analysis, HIV infection was associated with a four‐fold increased risk for VTE among pregnant and postpartum women (95% CI, 1.97‐ 6.63, P < 0.001). In addition, medical co‐morbidities, in particular peripartum cardiomyopathy, (OR, 11.04, 95% CI, 3.90–31.25), pre‐eclampsia with foetal growth restriction (OR, 6.88, 95% CI, 1.91–24.79), preterm delivery (OR, 7.60, 95% CI, 2.80–20.62), caesarean delivery in labour (OR, 3.17, 95% CI, 1.13–8.87), postpartum haemorrhage (OR, 22.60, 95% CI, 5.75–88.84) and prolonged hospital admission (OR, 7.78, 95% CI, 2.38–25.45) were independent risk factors for VTE. In 41 women thrombophilia screening was performed. Protein S deficiency was confirmed in five patients (three of which were HIV infected with virologic suppression) and the prothrombin gene mutation (not the classic G20210A mutation) was confirmed in a single patient.Summary/Conclusion:This study demonstrated that the incidence of VTE complicating pregnancy in Black South Africans is higher than the reported prevalence in White and Asian population groups. The findings of this study support many of the existing guideline recommendations and may provide valuable information to local obstetricians for identifying high‐risk pregnant and postpartum women requiring thromboprophylaxis. In addition, HIV emerged as a significant risk factor for VTE in this study population.