Risk Asessment and Thromboprophylaxis for Venous Thromboembolism (VTE) in the Antenatal Population in a Tertiary Health Facility in Nigeria

Aim: To review the venous thromboembolism (VTE) risk assessment and thromboprophylaxis in the antenatal population in a tertiary health facility in Nigeria and to perform a retrospective VTE risk assessment of the patients with a view of determining those patients that would have needed VTE prophylaxis.

Design: It was a retrospective cross-sectional study.

Place and Duration of Study: The study was carried out at the University of Port Harcourt Teaching Hospital (UPTH), Port Harcourt, Nigeria from the 1st of February to the 30th of April, 2020.

Materials and Methods: The following data were extracted from the hospital notes of 347 consecutive antenatal patients: history/demographic characteristics, risk factors for VTE, thromboprophylaxis, diagnosis and treatment of VTE, using the RCOG guideline 37a of 2015 as a benchmark for comparison. Data was analysed with the aid of a Statistical Package for Social Science (SPSS) software, version 18.

Results: VTE risk assessment and thromboprophylaxis was not a routine practice at the UPTH. Apart from antenatal admission, the most frequent VTE risk factors in pregnancy were BMI ≥30, Parity ≥ 3, Age > 5 years and current pre-eclampsia at 48.48%, 41.04%, 36.04% and 15.56% of the study population respectively. 131 (37.75%) of the 347 antenatal population fulfilled the criteria for venous thromboprophylaxis with low molecular weight heparin (LMWH) but they were not assessed and the drug was not given. 63 (18.16%) of the study population was to receive LMWH from 28 weeks of pregnancy while 68 (19.60%) of them were to be given from the first trimester. The prevalence of VTE was however very low at 0.02% (1 patient out of the 347 maternities), irrespective of the fact that 41 (11.82%) of the patients had symptoms and signs of VTE.

Conclusion: 131 (37.75%) out of the total 347 antenatal patients fulfilled the criteria to be given thromboprophylaxis but the prevalence of VTE was low at 0.02%. It was therefore recommended that a unified Nigerian national guideline should be written.