Asian Hematology Research Journal

Microcytic transformation and erythropoietic failure in pregnancy are commonly attributed to iron deficiency and physiological haemodilution; however, the independent and combined contributions of chronic H. pylori infection and occult gastrointestinal blood loss to anaemia severity remain poorly characterised, particularly in Nigerian obstetric populations. This comparative cross-sectional study enrolled 100 pregnant women in four groups: 40 healthy pregnant women (HPW) and 20 women each who were H. pylori-positive (H. P+), faecal occult blood (FOB)-positive (FOB+), or positive for both. Haemoglobin, packed cell volume, and red-cell indices - mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and mean corpuscular volume (MCV) - were measured and stratified by trimester and infection status. One-way analysis of variance with Tukey's HSD post hoc test assessed intergroup and trimester differences, while Pearson's correlation assessed associations with fibrinogen. Anaemia severity increased progressively across groups, from a mean haemoglobin of 12.07 ± 1.58 g/dL in HPW to 9.03 ± 2.01 g/dL in the co-positive group (p < 0.0001), and packed cell volume followed the same pattern (36.20 ± 4.05% to 28.21 ± 5.14%; p < 0.0001). The co-positive group was significantly more anaemic than either single-positive group (all pairwise p < 0.05) and showed the most marked microcytic, hypochromic pattern (MCV, 78.22 ± 2.33 fL; MCH, 24.67 ± 1.30 pg; MCHC, 30.89 ± 0.89 g/dL; all p < 0.0001 vs HPW). Trimester analysis showed distinct patterns: women in the H. P+ group had a marked MCV decline (88.00 to 79.00 fL; p = 0.001) by the second trimester, whereas the FOB+ group retained normocytosis until the third trimester (84.00 to 78.33 fL). MCHC declined significantly across trimesters in the H. P+ and co-positive groups, but not in the FOB+ group. These findings indicate that H. pylori infection was associated with an earlier, progressive microcytic hypochromic anaemic pattern, whereas isolated FOB positivity was associated with a later, milder iron-deficient pattern.