Correlation of midtrimester amniotic fluid cytokine concentrations with adverse pregnancy outcome in terms of spontaneous abortion, preterm birth, and preeclampsia

Abstract

Objective: To assess midtrimester amniotic fluid concentrations of three major proinflammatory cytokines (IL-6, IL-8, and TNF-α) in asymptomatic pregnancies with adverse outcomes. Methods: A prospective follow up study at the Charité University Hospital, Berlin, Germany of women with uncomplicated singleton pregnancies at second trimester and amniocentesis. Concentrations of IL-6, IL-8, and TNF-α were measured by enzyme-linked immunosorbent assay following amniotic fluid assessment by midtrimester amniocentesis performed from gestation days 15 weeks 0 days up to 20 weeks 6 days. Values from normal pregnancies were compared to those from pregnancies having adverse outcomes of spontaneous abortion, preterm delivery, preeclampsia, or eclampsia. Main outcome measure IL-6, IL-8 and TNF-α in relation to adverse pregnancy outcome. Results: A total of 298 consecutive patients were evaluated. Median patient age was 35 years (range 19–43). Controls consisted of 273 women who delivered without further complications after 37 weeks gestation. The range values of IL-6, IL-8, and TNF-α in the control group were 4.9–2620 pg/mL, 36.2–5843 pg/mL, and 8.0–28.2 pg/mL, respectively. Patients with adverse pregnancy outcome (n = 25) were classified into three groups: spontaneous abortion group (n = 4), preterm delivery group (n = 17), and preeclampsia/eclampsia group (n = 4). There were no significant differences in IL-6, IL-8, and TNF-α between controls and study groups, regardless of the type of complication (p > 0.05). Conclusion: Midtrimester amniotic fluid concentrations of the proinflammatory cytokines IL-6, IL-8, and TNF-α are not predictive of adverse pregnancy outcome in terms of spontaneous abortion, preterm delivery or preeclampsia/eclampsia in our study population.

Keywords::

• cytokines
• amniotic fluid
• midtrimester
• subclinic intraamniotic inflammation
• preterm birth
• spontaneous abortion
• preeclampsia
• amniocentesis
• interleukin-6
• interleukin-8
• TNF-α

Acknowledgements

The authors would like to thank medical laboratory technologist Fr. Korlach for her excellent technical assistance.

Declaration of interest: The authors declared no conflict of interest.