Anemia of inflammation is a predictor of the progression of postoperative infection in obstetrics

BACKGROUND: There is an insufficient number of studies studying the association of postpartum infectious and inflammatory complications with anemia of inflammation, which undoubtedly contributes to the risk of postpartum infection and the severity of its course.

AIM: To assess the prevalence of anemia of inflammation in pregnant women, to determine its prognostic value as an independent predictor of the progression of endometritis after caesarean section.

MATERIALS AND METHODS: A retrospective study of case histories and data from primary medical records of 648 puerperas delivered by caesarean section has been carried out. 406 of the patients have been diagnosed with endometritis after caesarean section and 242 — with a physiological course of the postoperative period. Anemia during pregnancy has been diagnosed with a decrease in hemoglobin <110 g/l (in the first trimester) and <105 g/l (in the second and third trimesters). Primary iron deficiency was determined by the level of serum ferritin. Anemia of inflammation has been diagnosed after exclusion of iron deficiency in the presence of documented signs of an inflammatory process (chronic diseases) and in accordance with the international hematological criteria: normochromic normocytic anemia, normo-/hyperferritinemia (serum ferritin >30 μg/l), hypotransferrinemia (transferrin <2 g/l) and the level of C-reactive protein in the blood (> 6 mg/l).

RESULTS: Anemia of inflammation can be attributed to the most significant predictors of the development of endometritis. The odds ratio for this factor was 4.12 (95% confidence interval 1.28–6.19; p < 0.001). The study has also shown that significant factors in the development of endometritis after caesarean section are obesity (odds ratio 3.45; 95% confidence interval 1.14–5.11; p = 0.005), asymptomatic bacteriuria (odds ratio 3.68; 95% confidence interval 1.31–4.94; p < 0.001), carbohydrate metabolism disorders (odds ratio 2.84; 95% confidence interval 1.54–3.52; p = 0.012) and arterial hypertension (odds ratio 2.14; 95% confidence interval 1.12–4.04; p = 0.032).

CONCLUSIONS: The prevalence of anemia of inflammation in pregnancy is 2.1%. Anemia of inflammation complicates the course of pregnancy 5.5 times more often in puerperas with endometritis after caesarean section (27.4 vs. 4.9%; χ² = 52.1; p < 0.001), which makes it possible to classify it as a significant predictor of the development of postoperative infectious and inflammatory complications.