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 Outpatient Antibiotics Following Previable Rupture of Membranes (pPPROM) Between 18 0/7 and 22 6/7 Weeks Gestational Age (NCT05345457), a randomized phase 4 study. The primary outcome is Delivery Within 28 Days.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05345457 |
| Phase | Phase 4 |
| Condition | Pregnancy Preterm, Pregnancy Prom, PROM, Preterm (Pregnancy) |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University Hospitals Cleveland Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
Pregnant patients with previable prelabor rupture of membranes between 18 0/7 and 22 6/7 weeks gestational age, who were considering expectant management. The registry record does not report additional eligibility details.
Intervention
A seven-day course of oral azithromycin and amoxicillin. The record describes azithromycin as a single 500 mg dose administered immediately following randomization and before discharge; the full medication schedule is not reported in the registry record.
Comparator
No antibiotics, with management according to standard-of-care practices for previable preterm prelabor rupture of membranes in patients desiring expectant management.
Primary question
What proportion of patients undergoes spontaneous or medically indicated delivery within 28 days after previable prelabor rupture of membranes?
The clinical question is framed around latency: the time between membrane rupture and delivery. The primary endpoint reduces that interval to a binary outcome: delivery within 28 days or not within 28 days. The study was designed to compare the antibiotic strategy with no antibiotics, but the registry record reports that only one participant was enrolled and did not complete the study. It also states that no data were analyzed. Consequently, the record cannot provide a comparison of the groups or an estimate of the proportion meeting the primary endpoint.
The registry lists severe maternal morbidity and severe neonatal morbidity composites as secondary outcomes. Their results are not reported in the registry record. The information therefore describes the question the trial set out to address, rather than an answer about how the two management strategies compare.
3. Trial Design
The registry describes a randomized, controlled, non-placebo study with a parallel-group design. Participants were to be allocated to antibiotics or no antibiotics. Masking is listed as none, so the record does not describe a blinded comparison. The study is classified as Phase 4. Its sponsor is University Hospitals Cleveland Medical Center.
The planned antibiotic intervention was a seven-day oral course of azithromycin and amoxicillin. The registry describes a single 500 mg azithromycin dose immediately after randomization and before discharge. The full dosing schedule, including details not contained in that description, is not reported in the registry record. The control group was to receive no antibiotics and standard-of-care management for previable preterm prelabor rupture of membranes when expectant management was desired.
The registry lists a planned enrollment of 1 and reports that one participant was enrolled. That participant did not complete the study, and the primary outcome was not analyzed. The study status is terminated. The listed start date is 2023-01-13, and the primary completion date is 2024-02-26. The reason for termination is not reported in the registry record.
Randomization describes the intended assignment process; by itself, it does not ensure that a completed comparison is available. With no analyzed primary outcome, the record does not provide an estimate of delivery within 28 days for either arm, nor an estimate of the difference between arms. Details of the randomization sequence, allocation concealment, sample-size justification, and planned statistical analysis are not reported in the registry record.
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 | Antibiotics | No Antibiotics |
|---|---|---|
| STARTED | 0 | 1 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 0 | 1 |
Reasons for not completing this period:
| Reason | Antibiotics | No Antibiotics |
|---|---|---|
| Pt opt for D&E, withdrawn | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: Only one study participants was enrolled and did not complete the study, no data analyzed.
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.
Population: No one was enrolled in the Antibiotic arm, only 1 study participant was enrolled study wide.
| Characteristic | Unit | Antibiotics | No Antibiotics | Total |
|---|---|---|---|---|
| Participants analysed | 0 | 1 | 1 | |
| Age, Categorical: <=18 years | Participants | — | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | — | 1 | 1 |
| Age, Categorical: >=65 years | Participants | — | 0 | 0 |
| Sex: Female, Male: Female | Participants | — | 1 | 1 |
| Sex: Female, Male: Male | Participants | — | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | — | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | — | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | — | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | — | 0 | 0 |
| Race (NIH/OMB): White | Participants | — | 1 | 1 |
| Race (NIH/OMB): More than one race | Participants | — | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | — | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Delivery Within 28 Days, measured over 28 days from date of rupture.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the proportion of patients who undergo either spontaneous or medically indicated delivery within 28 days after previable prelabor rupture of membranes. The registry frames this as a measure of latency, meaning the time from rupture to delivery. Its timeframe is stated as 28 days from the date of rupture, while the outcome description refers to 28 days from diagnosis. The record does not explain whether those reference points were intended to differ.
A fixed-window proportion can make an outcome easier to interpret than an unrestricted time interval: it identifies whether delivery occurred within a specified period. It does not, by itself, describe the exact timing of delivery within that period or the experience of participants whose follow-up is incomplete. General statistical context: outcomes defined over a time window require clear rules for when the window starts and how incomplete follow-up is handled. Those rules are not reported in the registry record.
The registry reports that the only enrolled participant did not complete the study and that no data were analyzed. Thus, there is no observed primary-endpoint proportion or between-arm comparison in the posted results. The record also lists severe maternal and severe neonatal morbidity composites as secondary outcomes, but their results are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical fact is that there is no analyzed primary-outcome result. Although the study was randomized and intended to compare antibiotics with no antibiotics, one participant was enrolled and did not complete the study. The registry explicitly says that no data were analyzed. Therefore, it is not possible to estimate the proportion delivering within 28 days in either group, compare the groups, or quantify uncertainty around a treatment contrast.
This is different from a result showing no difference. A no-difference conclusion would require outcome information from which a comparison could be estimated. Here, the primary outcome was not analyzed, so the registry record supplies no estimate to interpret as either a difference or a lack of difference. Neither a favorable nor an unfavorable effect can be inferred from the absence of an analysis.
The enrollment figure and the sample size needed for a future study answer different questions. The record reports an enrollment of 1, but does not report a sample-size justification. Any planning illustration based on an observed effect is not a description of the trial's achieved precision or power. Since no primary effect estimate is reported, such illustrations cannot substitute for an observed comparison. The registry's stated sample-size illustration assumptions include a two-sided significance level of 0.05, equal allocation, and a normal approximation; these describe the illustration framework, not evidence from completed analyses.
The serious adverse event listing needs similarly cautious interpretation. The antibiotics group has zero participants at risk in the posted serious-event figures. The no-antibiotics group has one participant at risk and one affected participant, with no deaths listed. The registry also lists cervical laceration and uterine laceration as serious-event terms, each at 100.0%. These entries are descriptive registry counts; they do not establish a comparative safety profile, and the small amount of recorded information cannot support stable estimates of event frequency. The entries should not be treated as proof of causation.
The trial status is terminated, but the reason for termination is not reported in the registry record. The available record does not indicate why the participant did not complete the study, whether the trial stopped for a particular operational reason, or whether any additional unposted information exists. Those unknowns should remain unknown rather than being filled in by speculation.
Overall, the posted information describes a planned randomized comparison and limited registry event counts, but not an analyzed efficacy result. The primary question remains unanswered by the results in the registry record. The evidence cannot establish either a difference or equivalence between the strategies.
9. Statistical Methods Explained
Statistical interpretation depends first on identifying what was measured and whether an analysis was completed. The primary endpoint is a proportion: whether a participant experienced delivery within the stated 28-day window. A comparison of two proportions would ordinarily summarize the outcome in each group and estimate a contrast between those groups. The registry record supplies neither group-specific primary-outcome results nor a calculated contrast. It states that the only enrolled participant did not complete the study and no data were analyzed.
What would a confidence interval mean?
General statistical context: a confidence interval expresses the uncertainty associated with an estimate under a specified statistical method. A narrow interval generally indicates greater precision than a wide interval, while an interval that is wide indicates that the data are compatible with a broader range of values. A confidence interval is not a guarantee that the true value lies within its limits. In this trial record, there is no primary estimate or interval to interpret. The absence of an interval is not evidence that uncertainty is small; it reflects that no primary-outcome analysis is reported.
What does randomization contribute?
General statistical context: random assignment is intended to make treatment groups comparable, on average, with respect to measured and unmeasured characteristics. This supports a causal comparison when enough participants are enrolled, outcomes are observed, and the analysis follows a suitable plan. Randomization does not itself generate an effect estimate, prevent missing outcomes, or guarantee balance in a very small realized sample. Here, the registry identifies the study as randomized, but the participant did not complete the study and the primary outcome was not analyzed. There is consequently no completed randomized comparison to interpret.
How should the endpoint definition be read?
The registry describes the endpoint as delivery within 28 days, while the timeframe says 28 days from the date of rupture and the description says 28 days from diagnosis. These phrases may refer to the same point in this study, but the record does not clarify that. General statistical context: the start of a time window matters because changing it can change which events count. The registry record does not report additional operational rules, such as how to classify a participant with incomplete follow-up or how the outcome would be adjudicated.
A proportion within a fixed window is distinct from a time-to-event analysis. General statistical context: a time-to-event method can use information on when an event occurs and may account for participants whose event time is not observed during follow-up, subject to assumptions and a prespecified analysis plan. The record does not report a time-to-event analysis plan or results. It is therefore not appropriate to infer that such a method was used merely because the study concerns latency.
What do the planning assumptions say?
The registry describes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It says that the effect to detect is a stated fraction of the observed effect, and that non-time-to-event planning outputs are participants per arm for 80% or 90% power; time-to-event outputs use total events. These are planning conventions, not results from participants. No sample-size justification for the trial's own design is reported in the registry record. No observed primary effect is reported either, so a planning illustration cannot be read as trial evidence or as observed power.
General statistical context: power is a design-stage probability of detecting a specified effect under assumed conditions. It is not a measure of whether a completed study's result is true, and it cannot replace an estimate with its uncertainty. In a trial with no analyzed primary endpoint, power calculations cannot supply the missing outcome. A sample-size illustration is hypothetical and depends on its assumptions; it does not show that an effect was observed.
Why can event counts be unstable?
General statistical context: sparse data contain few observations for estimating event rates or group differences. Estimates from sparse data can be highly sensitive to individual observations and may have substantial uncertainty. Standard approximations may also perform poorly when counts are very small. The serious-event figures list one participant at risk in the no-antibiotics group and none in the antibiotics group. These counts are descriptive and do not support a dependable comparative safety estimate. The registry does not report inferential analyses of these events.
Over-dispersion is a general concern for count outcomes when observed variability exceeds what a chosen probability model expects. It can make standard errors too small if not handled appropriately. The registry does not report a count-model analysis, so there is no basis to say that over-dispersion was assessed or affected an analysis. This concept is relevant generally to count data, not an explanation of the posted event figures.
Finally, registry outcomes and statistical analyses are not interchangeable. An outcome can be listed as planned without a result being available. The primary endpoint and secondary morbidity composites are named in the record, but the primary outcome has no analysis and secondary results are not reported in the registry record. Statistical conclusions should therefore be limited to the design and the explicitly posted counts, without converting missing analyses into estimates.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary outcome, delivery within 28 days, and two secondary outcomes: a severe maternal morbidity composite and a severe neonatal morbidity composite. The results for the secondary outcomes are not reported in the registry record. The record reports no analysis of the primary endpoint. The number of outcome measures is listed as 3, but a count of measures does not establish how statistical testing was planned.
Multiplicity arises when multiple statistical hypotheses are tested. General statistical context: if several tests are interpreted together without an appropriate plan, the chance of at least one apparently notable result can increase. Methods for controlling or otherwise addressing multiplicity depend on the study's objectives and analysis plan. Whether the trial planned any adjustment, hierarchy, or other strategy is not reported in the registry record. No conclusions about multiplicity handling can be drawn from the outcome list alone.
The record does not report an analysis population, such as whether the primary analysis was intended to follow randomized assignment regardless of treatment received. It also does not describe a missing-data method, rules for incomplete follow-up, or how participants with missing outcomes would have been classified. The only participant enrolled did not complete the study, and the primary outcome was not analyzed. It is not possible to determine from the record why follow-up was incomplete or how the study team intended to handle that circumstance.
These omissions matter because missing outcomes can affect the interpretation of a comparison, while the chosen analysis population determines which participants contribute to an estimate. General statistical context: an analysis plan set in advance can help distinguish planned tests and populations from decisions made after seeing outcomes. The analysis plan and the reason for termination are not reported in the registry record, so neither can be reconstructed.
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 |
|---|---|---|---|
| No Antibiotics | 1 | 1 | 100.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Antibiotics | 0 of 0 |
| No Antibiotics | 0 of 1 |
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 |
|---|---|
| Antibiotics | 0 of 0 |
| No Antibiotics | 0 of 1 |
Most frequent serious adverse event terms
| Event term | Organ system | Antibiotics | No Antibiotics |
|---|---|---|---|
| Cervical laceration | Pregnancy, puerperium and perinatal conditions | 0 of 0 | 1 of 1 |
| Uterine Laceration | Pregnancy, puerperium and perinatal conditions | 0 of 0 | 1 of 1 |
Serious events with the highest arm-level rate: cervical laceration (100.0%), uterine laceration (100.0%).
The serious adverse event figures are counts within the registry's arm listings, not a comparative safety analysis. For Antibiotics, the record lists 0 participants at risk and 0 affected participants for serious events, 0 at risk and 0 affected for other events, and 0 deaths. For No Antibiotics, it lists 1 participant at risk and 1 affected by a serious event, 1 at risk and 0 affected by other events, and 0 deaths.
The registry lists cervical laceration and uterine laceration among the top serious-event terms, each at 100.0%. These are the terms and percentages as recorded. The record does not explain the event-level relationship between these terms, whether they refer to the same participant, or the basis for attributing an event to a study arm. It also does not provide enough information to infer causation.
With only one participant enrolled and no analyzed primary outcome, the adverse-event entries cannot establish relative risks, comparative rates, or a reliable safety pattern. The antibiotics group's zero at-risk count is not evidence that the intervention had no serious adverse events in a meaningful comparative sense. The reason the trial was terminated and the circumstances of the participant's noncompletion are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The registry record establishes that this was intended as a randomized, non-placebo comparison of oral outpatient antibiotics with no antibiotics for patients with previable prelabor rupture of membranes in the stated gestational-age range. It also identifies delivery within 28 days as the primary endpoint and names severe maternal and neonatal morbidity composites as secondary outcomes. These details explain the study question and its planned design.
The record does not establish the effect of antibiotics on delivery within 28 days. One participant was enrolled, did not complete the study, and had no analyzed primary outcome. There are no reported group-specific primary-outcome proportions, effect estimates, confidence intervals, or primary-outcome tests. This lack of results should not be interpreted as showing that the groups were alike, nor as showing that one strategy was better. It means the registry record does not provide an analyzed comparison.
The limited serious-event counts are also not a basis for concluding that one arm is safer. Counts from one participant and the absence of an inferential safety analysis cannot characterize comparative risk. The serious-event terms listed in the registry should be read as descriptive entries, not as proof that treatment caused an event or that the same event pattern would be expected in a larger study.
The record does not report the reason for termination, the reason for noncompletion, a sample-size justification, or a detailed statistical analysis plan. Those gaps limit interpretation of how the study was intended to proceed and why it ended. No assumptions about those matters can be made from the enrollment and status information alone.
In general, a randomized design can support a comparison when it yields completed outcome data analyzed according to a suitable plan. In this instance, the posted results do not contain such an analysis. The scientifically appropriate reading is that the clinical question remains unresolved by the registry results, not that the result is negative or that either management strategy has been shown to have a particular effect.
13. Why This Trial Matters Statistically
This trial matters statistically because its record illustrates the distinction between a planned randomized design and an informative completed comparison. Randomization is a design feature, but an effect estimate requires observed outcome data and an analysis. The registry reports one participant enrolled, noncompletion, and no primary-outcome analysis. The randomized label therefore cannot be treated as a result.
The endpoint also highlights the importance of specifying a time origin. The registry gives the timeframe as 28 days from the date of rupture and describes the outcome in relation to 28 days from diagnosis. A clear, consistent definition is necessary to determine which events fall within the window. The record does not resolve the wording, so interpretation should preserve that uncertainty rather than silently choose one definition.
The sparse safety entries show why counts need context. A participant count and event-term percentages can look precise, but they do not support stable comparisons when the underlying record includes only one participant. Statistical precision is determined by the information in the data, not by how exact a percentage appears. The listed percentages should not be mistaken for estimates that generalize beyond these entries.
The record also separates planning from evidence. Sample-size illustrations rely on assumptions and are not observed power or outcomes. Without a reported primary effect estimate, the planned comparison cannot be recovered from an illustration. More broadly, the record does not report the trial's own sample-size justification or statistical plan, leaving those design details unavailable.
For clinical research readers, the main lesson is interpretive restraint: distinguish what was planned, what was recorded, and what was analyzed. Here, the planned question is clear, but the posted results do not answer it. Recognizing that boundary prevents a terminated, unanalyzed study from being misread as evidence of no effect.
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.
The most consequential limitation is that only one participant was enrolled and did not complete the study. The registry states that no data were analyzed for the primary outcome. There is therefore no efficacy estimate, no group comparison, and no measure of precision for the primary question. The trial's terminated status further indicates that the planned comparison did not yield a reported primary analysis, but the reason for termination is not reported in the registry record.
The safety information is limited to the posted arm counts and serious-event terms. Those entries do not support a reliable comparison between antibiotics and no antibiotics. The record does not clarify the relationship between the two listed serious-event terms, nor does it report an inferential safety analysis. No causal conclusion can be made from the event listings.
Additional design and analysis details are unavailable. The sample-size justification, randomization procedure, allocation concealment, detailed statistical plan, analysis population, missing-data handling, and reason for the participant's noncompletion are not reported in the registry record. The record also does not explain the difference in wording between the endpoint's reference to diagnosis and the timeframe's reference to date of rupture.
The registry lists secondary morbidity composites, but their results are not reported in the registry record. As a result, the record does not provide analyzed evidence for those outcomes either. These limitations mean that the trial information describes intent and limited event reporting, rather than a completed statistical evaluation of the clinical question.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Outpatient Antibiotics Following Previable Rupture of Membranes (pPPROM) Between 18 0/7 and 22 6/7 Weeks Gestational Age — NCT05345457.
- Registry record last updated 2026-06-18; status last verified 2026-05.
- Results first posted 2026-06-18.
- 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
NCT05345457 is a Phase 4 randomized, non-placebo, parallel-group trial sponsored by University Hospitals Cleveland Medical Center. It compared a planned seven-day oral course of azithromycin and amoxicillin with no antibiotics and standard-of-care expectant management for previable prelabor rupture of membranes between 18 0/7 and 22 6/7 weeks gestational age. Masking is listed as none.
The primary outcome was delivery within 28 days. The registry lists severe maternal and severe neonatal morbidity composites as secondary outcomes. The study is terminated; one participant was enrolled and did not complete the study, and no primary-outcome data were analyzed. The reason for termination is not reported in the registry record. The posted serious-event counts are limited and do not support a comparative safety conclusion.