Haematological, Inflammatory and Coagulation Profiles in Pregnant Women with COVID-19 Infection: A Prospective Case–Control Study in a Tertiary Care Centre

Abstract

Background: COVID-19 is associated with systemic haematological and inflammatory alterations that may be superimposed on the physiological hypercoagulability of pregnancy. Comparative case–control data combining haematological, coagulation and inflammatory parameters in Indian obstetric populations are limited. Objectives: To compare haematological, coagulation, inflammatory and biochemical parameters between COVID-19-positive and COVID-19-negative pregnant women in the third trimester. Methods: A prospective case–control study was conducted in the Department of Obstetrics and Gynaecology of a tertiary care teaching hospital in Shivamogga, Karnataka. Third-trimester pregnant women with and without COVID-19 (confirmed by RT-PCR or rapid antigen test) were compared for hemoglobin, total and differential leucocyte counts, platelet count, PT, APTT, INR, D-dimer, LDH, CRP and serum ferritin. Continuous variables were summarised as mean ± SD or median (IQR) according to distribution and compared using the independent t-test or Mann–Whitney U test; categorical variables were compared using the chi-square or Fisher’s exact test. Two-sided P < 0.05 was considered significant. Results: The dataset comprised 124 pregnant women (62 COVID-positive, 62 COVID-negative), exceeding the 120 participants (60 per group) originally proposed; this discrepancy is noted explicitly. Age, gestational age and gravidity did not differ between groups. COVID-positive women had significantly higher total leucocyte count (mean 9585 ± 3047 vs 8091 ± 2232 cells/cu mm; P = 0.002), higher neutrophil percentage (median 74.0% vs 59.5%; P < 0.001), lower lymphocyte percentage (median 20.0% vs 28.0%; P < 0.001), higher neutrophil-to-lymphocyte ratio (median 3.70 vs 2.15; P < 0.001) and more frequent qualitatively positive CRP (40.3% vs 4.8%; P < 0.001) than COVID-negative women. Haemoglobin, platelet count, PT, APTT, INR, D-dimer, LDH and serum ferritin did not differ significantly, although D-dimer and ferritin showed a non-significant upward trend in the COVID-positive group. Conclusions: Pregnant women with COVID-19 showed neutrophilic leucocytosis, relative lymphopenia, elevated NLR and higher CRP positivity compared with COVID-negative pregnant women, consistent with a systemic inflammatory response. Coagulation parameters were not significantly deranged in this cohort. These are observational associations that do not establish causation; placental correlation requires dedicated histopathological data.

Keywords: COVID-19; pregnancy; third trimester; haematological parameters; neutrophil-to-lymphocyte ratio; case–control studies; placenta