OBJECTIVE Various combinations of hemogram parameters such as white blood cell (WBC), neutrophil (NEU), lymphocyte (LYM), platelet (PLT), neutrophil-lymphocyte ratio (NLR), mean platelet volume (MPV), and platelet-lymphocyte ratio (PLR) are used as inflammatory markers. In this study, we aimed to determine the potential role of hemogram count parameters in predicting preterm birth. METHODS The study included 212 singleton pregnant women aged 17-40 years who were diagnosed with preterm labor and had preterm delivery and whose gestational weeks were between 24 weeks and 36 weeks and 6 days. The control group included 120 pregnant women between the ages of 17 and 40 who were delivered at 37 weeks or later and had no obstetric complications were included. The preterm labor group was divided into 2 subgroups: early preterm (n:108) and late preterm (n:104). Inflammatory markers were compared separately for the 1st and 3rd trimesters among the study groups. Changes between the 1st and 3rd trimester values were also assessed. RESULTS When the 1st trimester and 3rd trimester hemogram parameters were analyzed, in the preterm group, WBC, NEU and NLR values were found to be increased and MPV value decreased. A statistically significant difference was found between WBC, NEU, MPV and NLR values (p<0.05). In the term group only the increase in MPV was statistically significant. Markers for prediction of preterm birth cut-off levels as in 1st trimester WBC >9450/mm3, NEU >6650/mm3, NLR >3.86, MPV <9050/mm3 and in thirt trimester WBC >11300/mm3, NEU >8350/mm3, NLR >4.69, MPV <9250/mm3. CONCLUSION In our study we have found that 1st and 3rd trimester hemogram parametes as WBC, NEU, MPV and NLR varies among term and preterm birth and could be useful as proinflammatory markers. More comprehensive studies in different populations are needed to apply the results of our study to clinical practice.