Identification of biomarkers for preterm delivery in mid-trimester amniotic fluid

Objective: We investigated whether the level of vascular endothelial growth factor (VEGF) and inflammatory markers in mid-trimester amniotic fluid have predictive value for spontaneous preterm birth in singleton pregnancy. Method: Our subjects were 72 pregnant women who were undertaken with amniocentesis from 16 to 19 weeks of gestation. 36 cases were women with preterm delivery, and other 36 cases were matched women with full-term delivery. Stored amniotic fluid was investigated after the delivery. The levels of matrix metalloproteinases-8 (MMP-8), interleukin-6 (IL-6), C-reactive protein (CRP), and VEGF were measured by enzyme-linked immunosorbent assay (ELISA) and Western blot. Results: The levels of MMP-8 and IL-6 in preterm group were significantly higher than control group (5.76 +/- 1.53 ng/ml vs 4.89 +/- 1.77 ng/ml and 170.54 +/- 55.69 pg/ml vs 141.92 +/- 57.21 pg/ml, respectively) (p < 0.05). In terms of VEGF, the levels were elevated in preterm group (30.76 +/- 4.06 pg/ml vs 2236 +/- 7.03 pg/ml) (p < 0.05). Conclusion: This study suggests that elevated levels of IL-6 and MMP-8 in amniotic fluid at mid-trimester are predictive of preterm delivery, and that VEGF which is representative of angiogenesis can be a new and useful predictor of preterm delivery. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.