In this study, the levels of ischemia modified albumin, biglycan and decorin in the serums of pregnant women hospitalized for preterm labor will be examined. Their serum levels will be compared between women having preterm and term delivery. Their accuracy will be asessed in predicting preterm birth.

The study will include 90 singleton pregnant women between the ages of 18 and 42 and gestational ages of 24 and 37 weeks.

Inclusion criteria:

• Singleton pregnancy
• Gestational age between 24 and 37 weeks
• Cervical dilatation less than 3 cm and cervical effacement less than 80%
• Uterine contraction ≥3 times at 30 minutes
• Intact amniotic membrane

Excusion criteria:

• Multiple pregnancy
• Preterm premature rupture of membranes
• Abnormal placentation (such as placenta previa)
• Uterin anomaly
• Maternal heart disease
• Inflammatory or infectious disease
• Preeclampsia
• Fetal growth restriction
• Congenital fetal anomaly
• Polyhydramnios
• Acute chorioamnionitis
• Medically induced preterm delivery

Patients who are hospitalized due to preterm labor will primarily receive bed rest and hydration. If cervical changes persist or if contractions continue after 2 hours after intravenous hydration, tocolytic treatment will be started. Calcium channel blockers will be used as tocolytic drug. Maternal corticosteroid (12 mg intramuscular betamethasone within 24 hours) will be given to accelerate fetal lung development. After 48 hours after steroid administration, tocolysis will be stopped. Demographic datas of the patients will be recorded. Patients will be followed until delivery. The gestational week will be determined according to the last menstrual date and will be confirmed by early ultrasonographic measurements. The gestational week at birth and the time between admission to the hospital and birth will be recorded. Delivery time will be divided into groups within 24 hours, 48 hours, 7 days, 14 days, and ≤37 weeks after admission. Mode of delivery, baby's birth weight, APGAR score will be recorded.

Venous blood samples will be taken from patients before medication. Serum samples will be stored in the cooler set to -80 °C until analysis. Levels of ischemia-modified albumin, biglycan and decorin levels will be examined by enzyme-linked immunosorbent assay (ELISA) method.

Statistical analysis:

After the assessment of the data, the variables between two groups will be compared by Mann Whitney U test, Student T test, Fisher Exact Test, Chi-Square Analysis. Regression model will be conducted in order to estimate the probability of the preterm birth. A value of p < 0.05 will be considered statistically significant.

Inclusion Criteria:

• Singleton pregnancy
• Gestational age is between 24-37 weeks
• Cervical dilatation less than 3 cm and cervical effacement less than 80%
• Uterine contraction ≥3 times at 30 minutes
• Intact amniotic membrane

Exclusion Criteria:

• Multiple pregnancy
• Preterm premature rupture of membranes
• Abnormal placentation (such as placenta previa)
• Uterine anomaly
• Maternal heart disease
• Inflammatory or infectious disease
• Preeclampsia
• Fetal growth restriction
• Congenital fetal anomaly
• Polyhydramnios
• Acute chorioamnionitis
• Medically induced preterm delivery

Singleton pregnant women between the ages of 18 and 42 and gestational ages of 24 and 37 weeks.

Patients who are hospitalized due to preterm labor. Preterm labor is defined as regular contractions (uterine contraction ≥3 times at 30 minutes) of the uterus resulting in changes in the cervix that start before 37 weeks of pregnancy.