Preterm delivery (PTD) before completed 37 gestational weeks, remains one of the most important clinical problems in obstetrics throughout the world, as it is the leading cause of neonatal mortality and morbidity. Preterm delivery exerts numerous negative long-term effects on the neonate, which is especially true for extremely preterm neonates delivered before 28 gestational weeks. But, despite numerous studies, the detailed mechanisms and biological pathways that lead to PTB still remain elusive. The aim of our study was to determine the relationship between sonographic cervical length (CL), fetal fibronectin (fFN), phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1), cytokines, such as interleukine-6 (IL-6), interleukine-2R (IL-2R) as well as tumor necrosis factor-alpha (TNF alpha), and spontaneous preterm birth (SPTB) up to 14 days from sampling. The studied biochemical markers in our study were only moderately successful in the prediction of preterm delivery. Further research is required in terms of the evaluation of cost-benefit of using such test to prevent subsequent unnecessary interventions in the low-risk group, as well as to achieve the benefits from such intervention in the high risk groups of patients
