Intrapartum Rapid GBS Testing in Patients Presenting With Threatened Preterm Labor

November 18, 2022 updated by: MemorialCare Health System
The purpose of this study is to evaluate the test characteristics of a rapid intrapartum real- time polymerase chain reaction (RT-PCR) compared to the intrapartum GBS culture as the standard in preterm patients presenting with threatened preterm labor or with obstetric indications for preterm delivery.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Group B streptococcus (GBS) or Streptococcus agalactiae is a gram-positive bacterium that colonizes 10-40% of maternal gastrointestinal and urogenital tract sites. Maternal colonization remains the primary risk factor and the leading cause of early onset GBS disease in infants in the United States. Transmission of GBS to the neonate in early onset GBS cases occurs at the time of labor and delivery, with a transmission rate of 52.5% if no intrapartum antibiotics are used. Of those neonates, 1-2% term infants and 8% of preterm infants will develop early onset disease.

The Centers for Disease Control (CDC) recommends universal screening at 35-37 weeks via culture of the vagina and rectum. If this is performed ≤5 weeks before delivery, it has a sensitivity of 85% and a negative predictive value of 95-98%. There is a downside to screening remote from delivery however; vaginal GBS colonization fluctuates in the same woman over time, thus rendering possibly inaccurate GBS results. It has been reported that at least 10% of antenatal GBS negative women turned positive at the time of labor. This may suggest that screening at the time of delivery is a more accurate method of predicting actual GBS colonization status. In fact, a majority of neonatal GBS sepsis occurs in infants born to mothers with a negative antepartum screening culture.

Currently, a standard GBS culture may take up to 3 days to obtain results. A rapid diagnostic test has more recently been studied as a possible method of GBS screening - real-time polymerase chain reaction (RT-PCR). Prior studies of RT-PCR, specifically the Cepheid GeneXpert GBS assay used at Miller's Children's and Women's Hospital, have reported sensitivity from 85-98.5% and specificity of 96-99.6% using data from term gestations. The CDC currently permits the use of RT-PCR as a rapid screening test for those with unknown status at term.

Several reports demonstrate that RT-PCR is a rapid, more sensitive method than standard culture for determining the intrapartum GBS colonization status. Some studies have also demonstrated the ability of RT-PCR to identify patients who would otherwise be missed by traditional GBS culture. A study by Mueller et al demonstrated that out of 64 patients with positive RT-PCR results, 10 were actually negative on culture. A cost-effectiveness analysis has demonstrated that PCR intrapartum screening strategy is not any less cost-effective than traditional culture and confers a significant decrease in early onset GBS disease in term gestations.

Preterm infants suffer the highest rate of mortality from GBS infection, with up to 30% mortality in those < 33 weeks affected by GBS sepsis. Identifying GBS colonization is thus imperative in the 7-11% of all pregnancies affected by preterm labor, given that they will not have undergone universal screening yet (which typically occurs at 35-37 weeks). While the CDC recommends giving antibiotics to patients with unknown GBS status at substantial risk for preterm delivery, implementation of this recommendation is poor.

Advantages of the RT-PCR are that its results will come back much more rapidly than the standard culture and may assist in management of these critical patients, 75 min vs 3 days, respectively. Accurate screening for GBS in a rapid fashion, especially in preterm infants, where the risk of GBS infection is most serious, can potentially allow antibiotics to be used appropriately.

The investigators seek to evaluate the utility of RT-PCR for screening of GBS in women at risk of preterm labor with an unknown GBS status. The investigators also aim to identify the ability of RT-PCR to identify GBS colonization in patients who would have otherwise been missed by culture.

Study Type

Interventional

Enrollment (Actual)

342

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Long Beach, California, United States, 90806
        • Miller Children's & Women's Hospital Long Beach

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • Age ≥ 18 years
  • Pregnant women presenting for unplanned obstetrical care at a participating clinical study site
  • Gestational age between 21 6/7 and 36 6/7 weeks
  • Subject has not participated in the study before
  • Subject agrees to complete all aspects of the study and provide informed consent in accordance with applicable regulations
  • Signs and/or symptoms suggestive of preterm labor, whereby the managing clinician suspects preterm labor
  • Uterine contractions (with or without pain)
  • Intermittent lower abdominal pain, dull backache, pelvic pressure
  • Vaginal bleeding during the second and third trimester
  • Menstrual-like intestinal cramping (with or without diarrhea)
  • Change in vaginal discharge (amount, color, or consistency)
  • Vague sense of discomfort characterized as "not feeling right"
  • Change in cervical exam (cervical dilation, effacement, or consistency)
  • Signs and symptoms necessitating preterm delivery (i.e abruption, preeclampsia, hemolysis elevated liver enzymes, low platelet (HELLP) syndrome, ruptured membranes, chorioamnionitis, fetal indications)

Exclusion Criteria:

  • Exposure to antibiotics within 1 week prior to enrollment (15)
  • Known GBS bacteriuria at the time of enrollment
  • Prior history of neonatal GBS sepsis

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: single arm
All patients will have GBS culture and real time PCR performed.
Other: GBS culture and real time PCR
patients with signs and symptoms of threatened preterm labor, or indications for preterm delivery will have GBS colonization screened by culture and real time PCR.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Sensitivity of intrapartum GBS real time PCR compared to intrapartum GBS culture
Time Frame: up to one and a half year
up to one and a half year
Positive predictive value of GBS Real time PCR performed intrapartum
Time Frame: up to one and a half year
up to one and a half year
Negative predictive value of GBS real time PCR performed intrapartum
Time Frame: up to one and a half year
up to one and a half year
Specificity of intrapartum GBS real time PCR compared to intrapartum GBS
Time Frame: up to one and a half year
up to one and a half year

Secondary Outcome Measures

Outcome Measure
Time Frame
Neonatal GBS septicemia
Time Frame: up to one and a half year
up to one and a half year
Composite neonatal morbidity
Time Frame: up to one and a half year
up to one and a half year
number of neonatal intensive care unit days
Time Frame: up to one and a half year
up to one and a half year
Neonatal mortality rate
Time Frame: up to one and a half year
up to one and a half year
necrotizing enterocolitis
Time Frame: up to one and a half year
up to one and a half year
Gestational age at delivery
Time Frame: up to one and a half year
up to one and a half year
vaginal delivery
Time Frame: up to one and a half year
up to one and a half year
Postpartum hemorrhage
Time Frame: up to one and a half year
up to one and a half year
Maternal intrapartum chorioamnionitis
Time Frame: up to one and a half year
up to one and a half year
Maternal postpartum endometritis
Time Frame: up to one and a half year
up to one and a half year
Neonatal respiratory distress
Time Frame: up to one and half year
up to one and half year

Other Outcome Measures

Outcome Measure
Time Frame
Neonatal intraventricular hemorrhage
Time Frame: up to one and half year
up to one and half year
Neonatal pneumonia
Time Frame: up to one and half year
up to one and half year
Neonatal osteomyelitis
Time Frame: up to one and half year
up to one and half year
Neonatal bacteremia
Time Frame: up to one and half year
up to one and half year
Neonatal meningitis
Time Frame: up to one and half year
up to one and half year
cesarean delivery
Time Frame: up to one and half year
up to one and half year
composite maternal morbidity
Time Frame: up to one and half year
up to one and half year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

MemorialCare Health System

Investigators

  • Principal Investigator: Alex Fong, MD, Maternal Fetal Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2015

Primary Completion (Actual)

June 1, 2018

Study Completion (Actual)

December 1, 2019

Study Registration Dates

First Submitted

July 23, 2015

First Submitted That Met QC Criteria

July 27, 2015

First Posted (Estimate)

July 30, 2015

Study Record Updates

Last Update Posted (Actual)

November 22, 2022

Last Update Submitted That Met QC Criteria

November 18, 2022

Last Verified

November 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 534-15

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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