An interventional study of GBS culture and real time PCR in Group B Streptococcus, sponsored by MemorialCare Health System. Completed at 1 site in United States. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2022-11-22.
Sponsored by MemorialCare Health System · Not applicable, Interventional, and Diagnostic
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.
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.
255 studies on the registry are indexed under Obstetric Labor, Premature; 38 are open to participants now.
This study's enrollment of 342 is above the median of 110 across 155 interventional studies indexed under Obstetric Labor, Premature.
Browse Obstetric Labor, Premature studies →MemorialCare Health System is the lead sponsor of 21 studies on the registry; 4 are open to participants now.
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Exclusion Criteria:
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.
Sensitivity of intrapartum GBS real time PCR compared to intrapartum GBS culture
Time frame: 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
Negative predictive value of GBS real time PCR performed intrapartum
Time frame: 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
Neonatal GBS septicemia
Time frame: up to one and a half year
Composite neonatal morbidity
Time frame: up to one and a half year
number of neonatal intensive care unit days
Time frame: up to one and a half year
Neonatal mortality rate
Time frame: up to one and a half year
necrotizing enterocolitis
Time frame: up to one and a half year
Gestational age at delivery
Time frame: up to one and a half year
vaginal delivery
Time frame: up to one and a half year
Postpartum hemorrhage
Time frame: up to one and a half year
Maternal intrapartum chorioamnionitis
Time frame: up to one and a half year
Maternal postpartum endometritis
Time frame: up to one and a half year
Neonatal respiratory distress
Time frame: up to one and half year
Neonatal intraventricular hemorrhage
Time frame: up to one and half year
Neonatal pneumonia
Time frame: up to one and half year
Neonatal osteomyelitis
Time frame: up to one and half year
Neonatal bacteremia
Time frame: up to one and half year
Neonatal meningitis
Time frame: up to one and half year
cesarean delivery
Time frame: up to one and half year
composite maternal morbidity
Time frame: up to one and half year
This study is completed, as verified in Nov 2022. You cannot join it, but the record below documents what was studied.
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