TNF-α And IL-8 As Prognostic Markers of Birth Outcome in Overweight and Non-Overweight Pregnant Women
Authors: Elksne Karlina , Jurka Antra , Rezeberga Dace 
Published: September 2013

Introduction. Overweight has become a major risk factor for various diseases. Compared with normal weight overweight pregnant women have an increased risk of various complications in childbirth - invasive fetal monitoring, perineal ruptures, operative vaginal deliveries, cesarean sections, increased gestational age at delivery, and increased maternal length of stay are present. Both pregnancy and childbirth is a conditions significantly affected by the the immune system. However, this relationship and the possibility of its practical use is still not fully explored.

Aim of the study. Our aim is to determine whether overweight have the same impact on obstetrical outcome as obesity, explore changes of Interleukin-8 (IL-8) and Tumor Necrosis Factor-alpha (TNF-α) levels in the first and second trimester of pregnancy, compare these changes in normal weight pregnant women and pregnant women with overweight, to clarify their relationship to pregnancy outcome and to determine whether these cytokines have the potential to serve as biomarkers for prediction of labor complications.

Material and methods. This was a prospective, longitudinal study were we enrolled 55 pregnant women in their first antenatal visit. Blood samples were taken at different weeks of pregnancy. TNF-α and IL-8 concentrations were measured by Luminex xMAP technology (Luminex Corporation). Statistical analysis was performed using LibreOffice Calc, the Fisher exact test, Ttest, Spearman’s rank correlation coefficient and a non-parametric Mann-Whitney-Wilcoxon test. For all statistical analyses, p<0.05 was considered statistically significant.

Results. Labor dysfunction and cesarean section were more frequently observed in women with high BMI. In cases of vaginal delivery ruptures were more often for patients in high BMI group but the difference is small. Although average birth weight was slightly lower in normal BMI group, the difference is not statistically significant (p=0.13). Male gender babies were more often for women with high BMI, but statistical difference is not significant (p=0.15). Comparing the levels of TNF-α and IL-8 in different weeks of pregnancy no statistically significant difference between the study groups was found. There was no strong tendencies in dynamics in TNF-α and IL-8 levels in differend first and second trimester weeks of pregnancy. No statistically significant differences in levels of TNF- α and IL-8 depending on the fetal macrosomia were observed, but IL-8 level correlated with labour dysfunction and mode of delivery.

Conclusions. Overweight is a risk factor for labor dysfunction and probability of CS. TNF-α and IL-8 levels in early pregnancy does not differ in women with and without elevated BMI. In first and second trimesters of pregnancy no dynamics in TNF-α and IL-8 levels in maternal serum is observed. IL-8 level in the second trimester is correlated with labour dysfunction and increased cesarean section risk. This is an important finding, but its clinical value still requires further research.