Evaluation of Serum Interleukin-6 and C-Reactive Protein Levels among Women During Term Labour

Aims: To determine the serum concentrations of C-reactive protein (CRP) and interleukin 6 (IL-6) as well as level of leukocytosis, as inflammatory contributory factors in women with uncomplicated term pregnancies before, during and after labour.

Study Design: This is a cross-sectional study.

Place and Duration of Study: The study was carried out in the Department of Obstetrics and Gynaecology of Babcock University Teaching Hospital (BUTH) and Department of Biochemistry, Babcock University, Ogun State Nigeria between June 2019 and February 2020.

Methodology: 45 venous blood samples were obtained from 34 selected women and grouped into three; prenatal (≥ 32 weeks, n = 18), labour (4 to 6 cm dilation, n = 12) and postnatal (≤ 24 hour postpartum, n = 15). Sixteen blood samples were also obtained from the umbilical cord. Levels of CRP and IL-6 were determined by Enzyme Linked Immunosorbent Assay (ELISA) techniques and the leukocyte count, by hematologic method. Differences in statistical mean were evaluated by one way analysis of variance (ANOVA) with Bonferroni post hoc comparison. The level of significance was set at P < 0.05.

Results: Concentration of serum IL-6 was significantly high during labour (1354.79 ± 189.16 pg/mL) compared to the prenatal (14.94 ± 4.86 pg/mL, P < .001) and postnatal (13.17 ± 3.06 pg/mL, P < .001) periods. The low level of CRP observed during active labour compared to the prenatal and postnatal periods did not reach significant difference. The levels of these inflammatory markers were low in the cord blood. Leukocyte counts (P = .011) as well as neutrophils (P = .014) and MID cell fractions (P = .004) were significantly higher during the postnatal period.

Conclusion: The high levels of serum IL-6 observed in this study supports human term labour as an inflammatory event not associated with increased leukocytosis.