Biochemical markers for the prediction of spontaneous pre-term birth

Abstract

Objectives: The aim of this study was to identify predictive biochemical markers for preterm labor. Methods: In this prospective study we included 225 asymptomatic Caucasian women consecutively enrolled at 24 weeks of gestation. The following data were collected only once at 24 weeks of gestation: vaginal pH, vaginal fFN, cervical and serum concentration of IL-6, IL-8 and TNFα, maternal blood serum, ferritin. Student's t-test, the χ 2-test and multiple linear regression were used as statistical methods. Results: There were no differences between the age of patients, parity and gestational age at sampling between women who delivered at term and those who delivered pre-term (<37 weeks’ gestation). There was a significant increase of cervical IL-6 (pre-term 608±1595 pg/l vs. at term 58.9±112 pg/l) and serum ferritin (pre-term μg/l 74.4±1.1 vs. at term 26.3±56.5 μg/l) in pregnant women who delivered pre-term ( P<0.05). No differences in cervical IL-8 and cervical TNFα between pre-term and term deliveries were found. Multiple linear regression confirmed that the vaginal pH value and cervical fFN test were the best predictive biochemical markers of pre-term birth (standardized coefficient Beta=0.33 and 0.22, respectively). Conclusions: In order to evaluate pregnancies for pre-term labor, the presence of pH>4.5 and a positive fFN test seems to be predictive of subsequent pre-term delivery.