This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Group B Streptococcus Response After Probiotic Exposure (NCT04721912), a randomized phase 3 study. The primary outcome is GBS Culture Result (Positive Versus Negative).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04721912 |
| Phase | Phase 3 |
| Condition | Group B Strep Infection |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 68 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of New Mexico |
| Results posted | Yes |
2. Clinical Question
Population
The study focused on pregnant women who tested positive for Group B Streptococcus (GBS). Its brief summary describes healthy, low-risk women at term. The registry record does not report detailed eligibility criteria, how GBS positivity was established before enrollment, or other participant characteristics. The primary endpoint was assessed at admission to Labor and Delivery (L&D), within the stated gestational-age timeframe of 36 - 42 weeks.
Intervention
Participants assigned to the intervention were to take oral probiotic study capsules once daily from enrollment or randomization at at least 36 weeks gestation until birth. The trial title identifies Florjajen digestion probiotics, and the intervention is described as a probiotic dietary supplement. The record does not report the probiotic formulation details, adherence results, or the duration actually taken by participants.
Comparator
The control group was assigned to standard of care: no probiotic capsules, with advice to continue routine prenatal self-care. The study was open-label, so masking was not used. The registry record does not describe additional care, if any, beyond the stated routine self-care instruction, or report whether other probiotic use was assessed.
Primary question
The primary question was whether prenatal oral probiotic use would reduce the number of women who tested positive for GBS at admission to L&D. The outcome was qualitative GBS culture status, recorded as positive versus negative at T2. The study was also designed as a feasibility study for a larger randomized trial in this setting. The registry record does not report an analyzed treatment comparison for this endpoint, so it does not establish the direction or size of any difference between groups.
3. Trial Design
This was a phase 3, randomized, open-label, parallel-group interventional trial sponsored by the University of New Mexico. Its title describes an open-label randomized control trial and feasibility study. The stated purpose was to assess the feasibility of a larger randomized trial of prenatal probiotic use among GBS-positive pregnant women at term. The record lists enrollment of 68 and a completed status.
Participants assigned to the probiotic dietary supplement arm were to take oral capsules once daily beginning at enrollment or randomization at at least 36 weeks gestation and continuing until birth. Participants assigned to standard of care were not to receive probiotic capsules and were advised to continue routine prenatal self-care. The registry record does not report the randomization sequence method, allocation concealment, or allocation ratio. It also does not give enough information to assess whether adherence matched the intended daily schedule.
The primary endpoint was GBS culture result, classified as positive or negative, at admission to L&D. The timeframe is listed as T2, admission to Labor and Delivery, at 36 - 42 weeks gestational age. Secondary outcomes listed in the record include probiotic pill count as an adherence measure, an antepartum gastrointestinal symptom score, and reports of adverse events in participants and their infants.
The study start date is 2020-12-24, and primary completion is listed as 2023-08-31. The record does not report the protocol’s detailed analysis plan, planned follow-up procedures, or the reasons for any departures from the intended design. Its completed status indicates the registry listing’s status, but does not by itself establish that every planned analysis or outcome was reported.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Standard of Care | Probiotic Dietary Supplement |
|---|---|---|
| STARTED | 34 | 34 |
| COMPLETED | 21 | 25 |
| NOT COMPLETED | 13 | 9 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Standard of Care | Probiotic Dietary Supplement | Total |
|---|---|---|---|---|
| Participants analysed | 34 | 34 | 68 | |
| Age, Continuous | years | 28.8788 (SD 5.40693) | 29.9688 (SD 6.36261) | 29.42 (SD 5.88) |
| Sex: Female, Male: Female | Participants | 34 | 34 | 68 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 20 | 20 | 40 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 11 | 10 | 21 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 3 | 4 | 7 |
| Race (NIH/OMB): Race – American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Race – Asian | Participants | 0 | 3 | 3 |
| Race (NIH/OMB): Race – Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Race – Black or African American | Participants | 1 | 0 | 1 |
| Race (NIH/OMB): Race – White | Participants | 21 | 21 | 42 |
| Race (NIH/OMB): Race – More than one race | Participants | 2 | 1 | 3 |
| Race (NIH/OMB): Race – Unknown or Not Reported | Participants | 10 | 9 | 19 |
| Relationship Status: Single/widowed | Participants | 7 | 12 | 19 |
| Relationship Status: Partnered/married | Participants | 24 | 18 | 42 |
| Relationship Status: Missing | Participants | 3 | 4 | 7 |
| Living Arrangements: Lives with others | Participants | 29 | 28 | 57 |
| Living Arrangements: Lives alone | Participants | 2 | 2 | 4 |
| Living Arrangements: Missing | Participants | 3 | 4 | 7 |
| Education Level: HS/GED/some college | Participants | 10 | 10 | 20 |
| Education Level: College | Participants | 12 | 13 | 25 |
| Education Level: Graduate Degree | Participants | 9 | 7 | 16 |
| Education Level: Missing | Participants | 3 | 4 | 7 |
| Socio-economic status: <$40,000 | Participants | 7 | 7 | 14 |
| Socio-economic status: $40,000-99,999 | Participants | 8 | 12 | 20 |
| Socio-economic status: >$100,000 | Participants | 9 | 9 | 18 |
| Socio-economic status: Prefer not to answer | Participants | 7 | 0 | 7 |
| Socio-economic status: Missing | Participants | 3 | 6 | 9 |
| Parity: Nulliparous | Participants | 13 | 11 | 24 |
| Parity: Multiparous | Participants | 20 | 20 | 40 |
| Parity: Missing | Participants | 1 | 3 | 4 |
6. Primary Endpoint
The registry lists the primary outcome as GBS Culture Result (Positive Versus Negative), measured over T2 (admission to Labor and Delivery; 36 - 42 weeks gestational age).
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is GBS culture result, categorized as positive or negative among participants at admission to Labor and Delivery. The listed assessment time is T2, at 36 - 42 weeks gestational age. This is a binary outcome: each recorded result falls into a positive or negative category. The registry record does not give the number of participants with either result in each randomized group.
The endpoint matches the study’s stated question about GBS positivity at the time of admission for birth. Measuring status at that time focuses on colonization close to delivery, rather than on a more distant assessment during pregnancy. It therefore reflects the specific timing named in the study objective. The record does not describe the culture collection procedure, laboratory methods, or criteria for an indeterminate or missing culture result.
For a binary endpoint, a treatment comparison would ordinarily describe the positive and negative results by group and estimate a contrast between groups, with uncertainty. Such an estimate can help distinguish the observed group pattern from the range of values compatible with sampling variability. No single comparison for the primary endpoint is reported in the registry record: the outcome has multiple categories or time points and was not reduced to one comparison in the posted results. Consequently, neither the direction nor the precision of a primary treatment effect can be interpreted from this record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically focused primary outcome: GBS culture status at admission to Labor and Delivery. It also provides the intended comparison between a daily probiotic capsule regimen and standard prenatal self-care without probiotic capsules. However, it does not report a primary-outcome result as a single comparison. In particular, no group counts for positive or negative cultures, effect estimate, confidence interval, or primary-outcome p-value are reported in the registry record.
This absence matters for interpretation. Knowing the endpoint definition and study design is not enough to tell whether the observed culture results differed between groups, in which direction they differed, or how precisely a difference was estimated. The trial’s enrollment figure and its completed status do not substitute for outcome data. They also do not establish that a treatment effect was present or absent.
The record gives structured adverse-event figures: in each arm, 34 participants are listed as at risk for serious adverse events and 0 as affected; the corresponding other-adverse-event figures are 34 at risk and 0 affected. Deaths are listed as 0 in each arm. These entries describe the registry’s reported safety counts. They do not provide a detailed account of event definitions, collection procedures, follow-up completeness, or the relationship of any event to the intervention. Zero recorded affected participants should therefore be read as a reported count in these fields, not as proof that no symptoms or events occurred in every possible sense.
The study was expressly framed as a feasibility study intended to inform a larger randomized trial. Feasibility outcomes and the listed secondary outcomes could be relevant to whether and how a larger study should be conducted. The registry record does not report their results, however, and does not state whether a feasibility threshold was met. No conclusion about recruitment, adherence, acceptability, or the performance of study procedures can be drawn from the outcome descriptions alone.
There are no analyses listed in the record. No adjusted or unadjusted primary comparison, uncertainty interval, or multiplicity procedure is reported. There is also no statistical analysis plan in the registry record to clarify whether the intended primary analysis would have used an intention-to-treat population, a per-protocol population, or another approach. Without those details and the endpoint results, statistical evidence for a group difference cannot be assessed.
The appropriate conclusion is limited: the registry record documents a completed randomized feasibility study with a defined endpoint and intervention, but it does not report an interpretable primary-outcome comparison. The posted information therefore supports description of the design and reported safety counts, not a conclusion about whether probiotic use changed GBS culture status.
9. Statistical Methods Explained
Several statistical ideas help explain what would be needed to interpret a randomized comparison, and what the registry record does and does not report. These are general explanations; they are not claims about analyses carried out in this trial.
How does randomization support a comparison?
In general, randomization assigns participants to study groups using a chance-based process. If implemented as planned, it can reduce systematic differences between groups at assignment, so a later outcome contrast is less vulnerable to confounding than a nonrandomized comparison. Randomization does not guarantee that groups will be identical, and it does not remove uncertainty due to the number of observed outcomes. The registry record says allocation was randomized, but does not describe the sequence-generation method, allocation concealment, or whether assignment was stratified. Those details are not reported in the registry record.
The study was open-label, meaning masking was not used. In general, lack of masking can affect behavior, reporting, co-interventions, or outcome assessment, depending on the endpoint and how it is measured. A culture result may involve laboratory assessment, but the record does not report whether laboratory staff were masked or how samples were processed. It is therefore not possible to assess those safeguards from the registry description.
What does a binary endpoint require?
The primary outcome has two categories, positive and negative GBS culture status. A group summary would ordinarily give the number with each category and the number assessed, followed by a prespecified contrast. Common contrasts for binary data include a difference in proportions, a ratio of proportions, or an odds ratio. These answer related but distinct questions and have different interpretations. No primary contrast is specified in the registry record, and no group outcome counts or effect estimates are reported. It would not be appropriate to construct a treatment estimate without those values and a defined analysis population.
A confidence interval is a general way to express uncertainty around an estimated contrast. It gives a range of values compatible with the data and the assumptions of the method, rather than guaranteeing that the true value lies within that range. A p-value addresses compatibility with a specified null model; it does not measure the size or clinical importance of an effect. Neither a confidence interval nor a primary-outcome p-value is reported in the registry record.
What do planning calculations mean?
In general, sample-size calculations depend on assumptions about the outcome frequency, the effect a study aims to detect, the significance level, allocation, and the statistical model. The registry record describes planning illustrations based on a fraction of an observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation. It also states that the illustrations are planning calculations, not the trial’s original design. No resulting planning values are reported in the registry record, and no observed primary effect is available from which to assess those illustrations. Such calculations should not be called observed power: they are hypothetical planning aids based on assumptions, not a measure of what the completed study achieved.
The record states that analyses are not listed. The analysis method, model specification, handling of covariates, and any adjustment strategy are therefore not reported in the registry record. No recalculated comparison is available. If an independently recalculated estimate were to conflict with a sponsor’s analysis, the sponsor’s own analysis would take precedence; the registry record does not report a sponsor analysis for the primary endpoint, so that comparison cannot be made.
Why do analysis populations matter?
In general, an intention-to-treat analysis compares participants according to their randomized assignment, regardless of adherence, while a per-protocol analysis focuses on participants who followed specified study procedures. These approaches can answer different questions and can be affected differently by missing outcome data or treatment discontinuation. The registry record does not state which analysis population was planned or used. It also does not report the number of participants with an assessable culture result in either group, so the degree of endpoint completeness cannot be evaluated.
Because the endpoint is binary, missing culture results cannot simply be treated as either positive or negative without a stated rule. General approaches might include complete-case analysis, imputation, or sensitivity analyses under different assumptions, but each depends on the reason data are missing and the analysis plan. The registry record does not describe missing-data methods or report missingness by group. None should be inferred from the enrollment figure or the safety counts.
10. Multiplicity, Missing Data and Analysis Populations
The registry record identifies a primary outcome and several secondary outcomes, including pill-count adherence, gastrointestinal symptom assessment, and adverse-event reports for participants and infants. It does not report a statistical analysis plan, a hierarchy of tests, or a method for controlling multiplicity. When multiple outcomes or comparisons are analyzed, the chance of at least one apparently unusual result can increase. In general, a prespecified hierarchy or multiplicity adjustment can help clarify how evidence across outcomes should be interpreted. The record does not say whether any such approach was planned or applied.
The primary endpoint is described as having multiple categories or time points, and it was not reduced to a single comparison in the posted results. The registry record therefore does not report a specific primary contrast, nor does it explain how results across categories or time points would be combined or prioritized. No treatment effect or statistical test should be inferred from the endpoint description alone.
Missing-data handling is also not reported in the registry record. The record does not state how missing culture results, incomplete adherence information, or absent secondary-outcome assessments were to be treated. It does not give the number with an available primary endpoint in each randomized group or describe reasons for missing data. These omissions limit assessment of the analysis population and the risk that observed results, if reported elsewhere, might depend on who had evaluable measurements.
The registry record lists no analyses. Thus it does not document which outcomes were tested, how many comparisons were conducted, whether analyses were adjusted, or whether the analysis followed a prespecified plan. This is different from evidence that no analyses were ever conducted; it means the registry record does not report them.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Standard of Care | 0 | 34 | 0.0% |
| Probiotic Dietary Supplement | 0 | 34 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Standard of Care | 0 of 34 |
| Probiotic Dietary Supplement | 0 of 34 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Standard of Care | 0 of 34 |
| Probiotic Dietary Supplement | 0 of 34 |
The structured adverse-event record lists 34 participants at risk for serious adverse events in the Standard of Care group and 0 affected. For the Probiotic Dietary Supplement group, it also lists 34 at risk and 0 affected. The other-adverse-event entries show 34 at risk and 0 affected in each group. Deaths are listed as 0 in each group, and no serious-event terms are listed.
These are reported counts, not comparative risk estimates. The record does not provide event descriptions, severity grading beyond the serious-versus-other classification, onset timing, attribution, or details of how events were collected. It also does not report follow-up completeness or explain the definitions used for the at-risk denominators. The secondary outcomes mention adverse events reported by participants and their infants, but infant-specific outcome counts are not included in these structured figures.
Accordingly, the figures mean that no affected participants or deaths are recorded in these registry fields. They do not establish that no adverse symptoms or events occurred, nor do they quantify safety differences between groups with precision. The safety counts should be read alongside the limited reporting detail and not as a complete account of all possible events.
12. What the Result Does, and Does Not, Mean
The registry record establishes the intended design and question: an open-label randomized comparison of daily prenatal probiotic capsules with standard of care, focused on GBS culture status at admission to Labor and Delivery. It also identifies the study as a feasibility study intended to inform a larger randomized trial. These details clarify what investigators set out to examine, but they are not outcome evidence.
The primary endpoint is not reported as a single analyzed comparison. The registry record does not give the positive and negative culture counts by group, an effect estimate, a confidence interval, or a primary-outcome test. It is therefore not possible to say from this record whether the groups differed, what direction any difference took, or how uncertain an estimate would be. The lack of a reported comparison should not be interpreted as a finding of no difference.
The record’s safety fields list zero affected participants for serious and other adverse events in each group and zero deaths. Those entries are limited to the structured counts and do not resolve questions about event collection, definitions, completeness, or infant-specific outcomes. The absence of listed event terms is not a substitute for a detailed safety report.
Likewise, the enrollment figure and completed status do not show whether recruitment or follow-up was feasible, whether participants adhered to the capsule schedule, or whether the planned study procedures worked as intended. The listed secondary outcomes could address some of these questions, but their results are not reported in the registry record.
The most defensible interpretation is that this record describes a randomized feasibility study and its intended endpoint, while leaving the primary treatment comparison and key feasibility findings unavailable. It cannot establish whether prenatal probiotic use changed GBS culture status or support a conclusion about the size, precision, or practical importance of any effect.
13. Why This Trial Matters Statistically
This trial is statistically notable because its stated objective was feasibility as well as a clinical outcome question. A feasibility study can help determine whether a larger randomized study can be conducted in a particular setting, including whether recruitment, intervention delivery, adherence measurement, and outcome assessment are workable. The registry lists several outcomes relevant to those issues, such as pill count and symptom assessment. Their results are not reported in the registry record, so the feasibility contribution cannot be assessed from the listed outcome descriptions alone.
The study also illustrates why a clearly named endpoint is not enough for interpretation. GBS culture status at admission to Labor and Delivery is defined as positive versus negative, with an assessment timeframe of 36 - 42 weeks gestational age. But a statistical treatment comparison requires reported outcome data and a defined analysis. Without group counts and an estimate with uncertainty, readers cannot distinguish the observed pattern from the uncertainty around it.
Open-label assignment is another design feature relevant to interpretation. Randomization can support a fair comparison, while lack of masking may matter for behavior, co-interventions, or outcome assessment. The registry record does not provide enough procedural detail to assess these possibilities, including whether laboratory assessment was masked.
Finally, the listed safety counts are limited and do not replace comprehensive outcome reporting. Together, these features make transparent reporting of the endpoint, analysis population, missing data, and feasibility outcomes especially important. The record identifies a question worth studying and documents the trial’s design, but does not report the information needed to judge its primary statistical result.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
Several limitations specific to this record constrain interpretation. The most consequential is that the primary endpoint is not reported as a single comparison. The record explains that the primary outcome has several categories or time points and was not reduced to one comparison. It does not give culture counts by group, an effect estimate, an interval estimate, or a test result. As a result, the main study question cannot be answered from the registry outcome information.
The trial is described as a feasibility study, but no feasibility results are reported. The record does not give recruitment performance, completion of planned assessments, adherence findings, or whether feasibility criteria were prespecified or met. Although these matters are central to the stated purpose, they cannot be inferred from the completed status.
Design and analysis details are also limited. The randomization method, allocation concealment, planned allocation ratio, statistical analysis plan, analysis population, and handling of missing data are not reported in the registry record. The record does not describe the laboratory procedures for culture assessment or whether assessors were masked. These omissions prevent a fuller assessment of potential bias and the validity of any eventual comparison.
The safety entries are counts without detailed event descriptions or collection procedures. The record does not report infant-specific adverse-event results, despite listing an infant adverse-event outcome. It also does not state the completeness of safety follow-up or the definitions used for each event category.
Finally, the record lists secondary outcomes but does not report their results or explain how multiple outcomes would be interpreted. These reporting gaps limit conclusions about both the primary endpoint and the broader feasibility and safety questions.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Group B Streptococcus Response After Probiotic Exposure — NCT04721912.
- Registry record last updated 2025-01-14; status last verified 2025-01.
- Results first posted 2025-01-14.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The University of New Mexico sponsored this completed phase 3 randomized, open-label, parallel-group trial, NCT04721912, titled “Group B Streptococcus Response After Probiotic Exposure.” Enrollment was 68. The study compared a probiotic dietary supplement with standard of care for GBS-positive pregnant women at term and was intended to assess feasibility for a larger randomized trial.
The primary outcome was positive versus negative GBS culture at admission to Labor and Delivery, at 36 - 42 weeks gestational age. The record does not report a single primary-outcome comparison, group culture counts, or an effect estimate. It lists secondary outcomes involving adherence, gastrointestinal symptoms, and adverse events. Structured safety entries report 0 affected participants for serious and other adverse events, and 0 deaths, in each group; additional safety details are not reported in the registry record.
The study start date is 2020-12-24, and primary completion is 2023-08-31. Its completed status does not supply the missing primary analysis or feasibility findings.