Reference values for interleukin‐6 in the amniotic fluid of asymptomatic pregnant women. (11th March 2023)

• Record Type: Journal Article
• Authors: del Barco, Ester; Franco‐Jarava, Clara; Vargas, Mireia; Maíz, Nerea; Arevalo, Silvia; Sánchez, Maria Ángeles; Avilés, Maria Teresa; Rodó, Carlota; Mendoza, Manel; Goya, Maria; Hernández‐González, Manuel; Carreras, Elena
• Is Part Of: Acta obstetricia et gynecologica Scandinavica. Volume 102:Number 4(2023)
• Page Start: 480
• Page End: 485
• Publication Date: 2023-03-11
• Subjects: amniocentesis -- amniotic fluid -- chorioamnionitis -- interleukin‐6 -- intra‐amniotic infection -- intra‐amniotic inflammation -- preterm labor -- spontaneous preterm delivery; Gynecology -- Periodicals; Pregnancy -- Periodicals; Obstetrics -- Periodicals; 618.05
• DOI: 10.1111/aogs.14524
• Languages: English
• ISSNs: 0001-6349

Abstract

Abstract: Introduction: Nowadays, proinflammatory factors are considered to play an important role in the pathophysiology of threatened preterm labor or chorioamnionitis. The aim of this study was to establish the normal reference range for interleukin‐6 (IL‐6) levels in the amniotic fluid and to identify factors which may alter this value. Material and methods: Prospective study in a tertiary‐level center including asymptomatic pregnant women undergoing amniocentesis for genetic studies from October 2016 to September 2019. IL‐6 measurements in amniotic fluid were performed using a fluorescence immunoassay with microfluidic technology (ELLA Proteinsimple, Bio Techne). Maternal history and pregnancy data were also recorded. Results: This study included 140 pregnant women. Of those, women who underwent termination of pregnancy were excluded. Therefore, a total of 98 pregnancies were included in the final statistical analysis. The mean gestational age was 21.86 weeks (range: 15–38.7) at the time of amniocentesis, and 38.6 weeks (range: 30.9–41.4) at delivery. No cases of chorioamnionitis were reported. The log10 IL‐6 values follow a normal distribution ( W = 0.990, p = 0.692). The median, and the 5th, 10th, 90th, and 95th percentiles for IL‐6 levels were 573, 105, 130, 1645, and 2260 pg/mL, respectively. The log10 IL‐6 values were not affected by gestational age ( p = 0.395), maternal age ( p = 0.376), body mass index ( p = 0.551), ethnicity ( p = 0.467), smoking status ( p = 0.933), parity ( p = 0.557), method of conception ( p = 0.322), or diabetes mellitus ( p = 0.381). Conclusions: The log10 IL‐6 values follow a normal distribution. IL‐6 values are independent of gestational age, maternal age, body mass index, ethnicity, smoking status, parity and method of conception. Our study provides a normal reference range for IL‐6 levels in the amniotic fluid that can be used in future studies. We also observed that normal IL‐6 values were higher in the amniotic fluid than in serum. Abstract : Interleukin‐6 is a cytokine that has been linked to the pathophysiology of preterm labor and chorioamnionitis. This study provides a normal reference range for IL‐6 levels in the amniotic fluid that can be used in future studies. This study also evaluates maternal and fetal factors that may potentially have an impact on IL‐6 values.