Haematological and Coagulation Parameters in Pregnant Women with Gestational Age-Matched COVID-19 Infection in Abuja, North Central Nigeria

This study compares haematological and coagulation parameters in pregnant women with confirmed COVID-19 infection versus gestational age-matched uninfected pregnant controls in Abuja, Federal Capital Territory, North Central Nigeria. COVID-19 induces both inflammatory and thromboembolic complications, and its interaction with the physiological haematological changes of pregnancy creates a complex, understudied risk profile in Nigerian obstetric settings. A case-control analytical study enrolled 100 RT-PCR confirmed COVID-19 positive pregnant women and 100 uninfected pregnant controls matched by gestational age at three tertiary facilities in Abuja. Full blood count, D-dimer, fibrinogen, prothrombin time, APTT, ferritin, and C-reactive protein were assessed. Severity of COVID-19 illness was graded by WHO criteria. Findings showed significantly elevated D-dimer, fibrinogen, and ferritin in COVID-positive pregnant women compared to controls. D-dimer was above 1,500 nanograms per millilitre (a proposed pregnancy-specific VTE threshold) in 42 percent of COVID-positive women versus 12 percent of controls. Thrombocytopenia was present in 24 percent of COVID-positive women compared to 8 percent of controls. Lymphopenia was prominent in COVID-positive women with moderate-to-severe illness. Haemoglobin levels did not differ significantly between groups, but the COVID-positive group showed significantly higher RDW. The study provides empirical data informing COVID-19 thromboprophylaxis decision-making in pregnant Nigerian women and recommends D-dimer monitoring with low-molecular-weight heparin consideration for moderate-to-severe cases. Keywords: COVID-19, pregnancy, coagulation, D-dimer, thromboembolism.