investigating association between second trimester maternal serum biomarkers and pre-term delivery

background: considering the effect of preterm delivery in morbidity and mortality of newborns, its precaution and prevention is so important. objective: to investigate the association between second trimester maternal serum biomarkers (human chorionic gonadotropin, alpha-fetoprotein, non-conjugated estrogen, inhibin a) and pre-term delivery. materials and methods: this is a historical cohort study that has been performed for 700 pregnant women, clients of nilou lab in the second trimester of pregnancy to take the quad marker test between march to september 2008. the information of mothers having required conditions to enter to study has been registered and after delivery, they called again to be interviewed. these data sets using statistical tests: chi-square test and roc curve was analysis. results: there is a direct relationship between preterm delivery and increase of alpha-fetoprotein (p=0.011) and inhibin a (p=0.03) serum level and. also, there is an inverse relationship between the non-conjugated estrogen (p=0.002) serum level and preterm delivery. moreover, there is not any relationship between the increase human chorionic gonadotropin (p=0.68) serum level and preterm delivery. conclusion: the increase in the alpha-fetoprotein and inhibin a and decrease in non-conjugated estrogen serum levels in the second trimester of pregnancy lead to enhance the probability of preterm delivery. moreover, if the current study is done with higher samples and different sampling environment, it may have different results.