Comparison of serum granulocyte colony-stimulating factor levels between preterm and term births

Abstract

Material and MethodsThis study was conducted between January 2011 and July 2011 in our perinatology clinic. Ethics approval was obtained from our institutional review board. Informed consent was given by all study participants. The study was designed as a prospective case-control study. PTB was defined as a delivery that occurs before the 37th week of gestation (9,10). Inclusion criteria in the study group were singleton pregnancies with a diagnosis of preterm labor leading to preterm birth at or before 37 weeks of gestation. Women who had preterm premature membrane rupture (P-PROM), clinical signs of intrauterine infection (uterine tenderness, fetal or maternal tachycardia, maternal fever, etc.), or bacterial infection in the cervical/vaginal culture were not included in the study or control groups. Also, women who had a history of maternal cardiac disease, cervical incompetence, cervical cerclage or conization, fetal anomaly, or vaginal bleeding were excluded from the study and control groups. A total of 600 singleton pregnant women were screened at 24-28 weeks of gestation and routinely followed up at the outpatient clinic until delivery. Demographic values of all pregnant women were recorded. Forty pregnant women delivered their infants spontaneously after preterm labor before 37 weeks of gestation. Also, 120 pregnant women were selected as a control group among these 560 women via a simple random sampling method, who delivered their infants after 37 weeks of gestation. All participants had 24-28-week plasma samples available for granulocyte colony-stimulating factor analysis. For both groups, maternal blood samples were collected at 24-28 weeks of gestation during a routine prenatal screening program in the outpatient clinic. Venous blood samples from patients were collected into sterile, silicone-coated tubes, centrifuged, and stored at -70°C. Maternal serum G-CSF levels were measured with the G-CSF Human Enzyme-Linked Immunosorbent Assay (ELISA) kit (Novex®; Invitrogen, Los Angeles, USA). The Statistical Package for the Social Sciences 14.0 (SPSS Inc.; Chicago, IL, USA) statistical package was used for the statistical analysis. Descriptive statistical methods (mean, standard deviation), as well as a comparison of quantitative data, MannWhitney U-test, chi-square test, and Student's t-test, were used for the determination of differences between the two groups. Statistically significant levels for the tests were set at a p value <0.05. Spearman's rank correlation coefficient rho was used for the correlation study. ResultsThe characteristics of 160 women and the comparison of the two groups are shown in Table 1. The difference of the mean age of the women between groups was not statistically significant (p=0.8). There were no significant differences in maternal serum G-CSF levels between groups (p=0.28). Smoking status was different between cases of PTB and fullterm pregnancies, but a statistically significant difference was not found (p=0.284). ROC curve analysis was performed for the prediction of...