Maternal Serum Osteopontin Levels in Pregnant Women Diagnosed With PPROM (OPN)

Maternal Serum Osteopontin Levels in Pregnant Women Diagnosed With PPROM: A Prospective Case-Control Study

Preterm prelabor rupture of membranes (PPROM) is defined as the rupture of the fetal membranes prior to the onset of labor and before 37 weeks of gestation; it occurs in approximately 2-3% of all pregnancies and accounts for a significant proportion of preterm births .

Current data indicate that PPROM is not merely a clinical condition limited to membrane rupture; rather, it is a biological process associated with loss of structural integrity in the fetal membranes, an inflammatory-oxidative stress response, and cellular aging . The fetal membranes constitute a dynamic barrier that provides mechanical and immunological protection for the fetus throughout pregnancy .

There is limited data in the literature investigating the relationship between osteopontin and preterm birth. In particular, it has been reported that osteopontin levels may be higher in amniotic fluid samples collected during the second trimester from pregnant women who subsequently experienced spontaneous preterm birth . However, the changes in maternal serum osteopontin levels in cases of PPROM and the clinical significance of these changes remain unclear. Therefore, osteopontin levels may vary across different biological compartments and at different stages of pregnancy. To address this knowledge gap, the present study aimed to compare maternal serum osteopontin levels between pregnant women diagnosed with PPROM and those with term membrane rupture.

Study Overview

• Status: Completed
• Conditions: Preterm Labor
• Intervention / Treatment: Diagnostic test: SERUM OSTEOPONTİN

Detailed Description

This study was designed as a single-center, prospective, observational case-control study. The study protocol was approved by the Ethics Committee of the Faculty of Social and Humanities, Faculty of Science, Engineering, and Health Sciences at Batman University (Decision No: 2026/04-09; Date: 02.04.2026). Work began after the ethics committee approved the study. The research was conducted in accordance with the principles of the Declaration of Helsinki, and written informed consent was obtained from all participants.

• Study Type: Observational
• Enrollment (Actual): 71

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Batman, Turkey (Türkiye)
    • Private Zilan Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Case Group (PPROM): Women were eligible for the PPROM group if they met all the following criteria: confirmed diagnosis of PPROM by clinical and/or ancillary tests, gestational age between 24+0 and 36+6 weeks, singleton pregnancy, age 18 years or older, and provision of written informed consent.

Control Group (Term ROM): Women were included in the control group if they met all the following criteria: rupture of membranes at term (gestational age ≥37+0 weeks), singleton pregnancy, age 18 years or older, provision of written informed consent, absence of signs of active infection, and no history of additional systemic diseases.

Description

Inclusion Criteria:

• For the case group (PPROM):
• Gestational age between 24+0 and 36+6 weeks
• Singleton pregnancy
• Age ≥18 years
• Provision of written informed consent
• Confirmed diagnosis of PPROM by clinical and/or ancillary tests
• For the control group (term rupture of membranes):
• Gestational age ≥37+0 weeks
• Rupture of membranes
• No signs of active infection
• Singleton pregnancy
• Age ≥18 years
• Provision of written informed consent
• No history of additional systemic diseases

Exclusion Criteria (for both groups):

• Multiple pregnancy
• Major fetal anomaly
• Fetal distress
• Intrauterine growth restriction (IUGR)
• Clinical chorioamnionitis
• Systemic infection
• Autoimmune or chronic inflammatory disease
• Smoking
• History of malignancy
• Gestational trophoblastic disease
• Diabetes mellitus
• Preeclampsia
• Other serious obstetric complications

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
PRETERM LABOR (1); The study group included pregnant women with a diagnosis of preterm premature rupture of membranes (PPROM) confirmed by clinical and/or diagnostic tests. The diagnosis was confirmed by observing the discharge of amniotic fluid from the cervical os during a sterile speculum examination and, when necessary, by confirmatory diagnostic tests. The study included pregnant women without additional systemic diseases and with blood pressure measurements within the normal range.	Diagnostic test: SERUM OSTEOPONTİN; At the time of diagnosis, 5 mL venous blood samples were collected from all participants for biochemical analysis. The samples were centrifuged at 3,000 rpm for 10 minutes to separate the serum, which was then stored at -80°C until analysis. Serum osteopontin levels were measured using a sandwich enzyme-linked immunosorbent assay (ELISA) kit (Human Osteopontin ELISA Kit, Cat. No: E1525Hu, BT Laboratory, China) in accordance with the manufacturer's protocol. This kit has been developed for the quantitative determination of osteopontin levels in serum, plasma, and other biological fluids. The assay principle is based on the pre-coating of microplate wells with an antibody specific to human SPP1. The osteopontin present in the samples was incubated with a biotinylated secondary antibody and a streptavidin-horseradish peroxidase (HRP) complex after binding to this antibody. Following the washing steps, a substrate solution was added, and the resulting color reaction was stopped with an ac; Other Names: OSTEOPONTİN
Control /Term labor (2); The control group included pregnant women with a singleton pregnancy who experienced membrane rupture at 37 weeks + 0 days of gestation or later, had no signs of active infection and no history of additional systemic diseases. It was confirmed that none of these cases had a history of membrane rupture prior to the 37th week of gestation. The control group was selected from volunteers who met the eligibility criteria at the time of their admission to the delivery ward, and written informed consent was obtained after they were informed about the study.	Diagnostic test: SERUM OSTEOPONTİN; At the time of diagnosis, 5 mL venous blood samples were collected from all participants for biochemical analysis. The samples were centrifuged at 3,000 rpm for 10 minutes to separate the serum, which was then stored at -80°C until analysis. Serum osteopontin levels were measured using a sandwich enzyme-linked immunosorbent assay (ELISA) kit (Human Osteopontin ELISA Kit, Cat. No: E1525Hu, BT Laboratory, China) in accordance with the manufacturer's protocol. This kit has been developed for the quantitative determination of osteopontin levels in serum, plasma, and other biological fluids. The assay principle is based on the pre-coating of microplate wells with an antibody specific to human SPP1. The osteopontin present in the samples was incubated with a biotinylated secondary antibody and a streptavidin-horseradish peroxidase (HRP) complex after binding to this antibody. Following the washing steps, a substrate solution was added, and the resulting color reaction was stopped with an ac; Other Names: OSTEOPONTİN

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maternal Serum Osteopontin Concentration	Description: Concentration of osteopontin (ng/mL) measured in maternal serum using a commercially available enzyme-linked immunosorbent assay (ELISA) kit (e.g., Human Osteopontin ELISA Kit, manufacturer name and catalog number to be specified). Blood samples are collected at the time of diagnosis of PPROM or term membrane rupture, within 48 hours before delivery. Unit of Measure: ng/mL (nanograms per milliliter) Time Frame: 48 hours (from diagnosis to sample collection) Reporting Metric: Mean osteopontin concentration (with standard deviation) will be reported for each group (PPROM and term membrane rupture). Between-group comparison will be performed using an appropriate statistical test (e.g., independent t-test or Mann-Whitney U test).	48 hours

Collaborators and Investigators

• Sponsor: Batman Training and Research Hospital
• Collaborators: Batman University

Study record dates

Study Major Dates

• Study Start (Actual): April 9, 2026
• Primary Completion (Actual): May 12, 2026
• Study Completion (Actual): May 12, 2026

Study Registration Dates

• First Submitted: May 21, 2026
• First Submitted That Met QC Criteria: June 2, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: June 2, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: preterm labor; osteopontin
• Additional Relevant MeSH Terms: Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Obstetric Labor Complications; Pregnancy Complications; Obstetric Labor, Premature
• Other Study ID Numbers: Decision No: 2026/04-09

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: IPD will not be shared as participants consented solely to the use of their data for journal publication, not to broader individual-level data sharing."

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No