Platelet Rich Plasma in Levator Ani Muscle Trauma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Platelet Rich Plasma in Levator Ani Muscle Trauma (NCT03021954), a randomized phase 2, phase 3 study. The primary outcome is Changes of Levator Hiatal Area During Valsava.

2. Clinical Question

The trial record frames the question around an anatomical measurement rather than a reported patient-centered outcome. The measurement was to be made using translabial three-dimensional ultrasound. The record describes the outcome as changes in lower hiatal area compared with baseline, but does not give numerical values for any group or time point. It also does not report a single contrast, such as a between-group difference at one follow-up time, so the available information cannot establish the size or direction of a treatment-group difference.

The brief summary says levator trauma, described as ballooning, often occurs after vaginal delivery and states that platelet-rich plasma injection showed reduced hiatal area and maintained levator muscle strength. However, the posted record does not include numerical results supporting that summary, and muscle strength is not identified as the primary endpoint in the outcome description. The clinical question that can be evaluated from the detailed outcome information is therefore limited to the planned anatomical measurement and its timing, not a quantified effect or a conclusion about clinical benefit.

3. Trial Design

The registry describes a randomized, parallel-group trial with triple masking and phase labels of phase 2 and phase 3. The record lists an enrollment of 116 and a completed status. The listed start is 2016-11, and primary completion is 2019-01. These record entries describe the trial as registered, but they do not establish how many participants were assigned, received the intervention, or contributed data to each analysis.

The intervention group was assigned platelet-rich plasma injected intramuscularly in the pelvic floor muscle immediately following labor and before perineoraphy, simultaneously with local anesthesia injection. The control group received no platelet-rich plasma intervention and had local anesthesia injection before perineoraphy. The registry identifies the intervention as biological. It does not specify the platelet-rich plasma preparation, dose, injection volume, or any additional procedural details, so those aspects cannot be characterized from this record.

Random allocation is intended, in general, to make treatment groups comparable at the start of a trial by using a chance-based assignment process. A parallel design means the groups are followed as separate groups rather than having participants cross from one assigned intervention to another. The record's triple-masking label indicates that masking was recorded, but it does not identify which roles or individuals were masked, or how masking was maintained. The allocation concealment procedure and randomization method are not reported in the registry record.

Although enrollment and completion status are recorded, participant flow, deviations from assigned treatment, and analysis populations are not described. The record also does not report the protocol's sample-size justification, a detailed statistical analysis plan, or the handling of interim analyses. The trial design can therefore be described from the registry's stated design labels and arm descriptions, but not reconstructed in detail.

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.

Before assignment: We obtained 116 primigravid women. Fifty-three subjects were drop-out failed to finish the study. Five subjects were excluded from the study cause were detected having avulsion (macro trauma) injury at 40 days post-partum evaluation that was considered as severe degree of trauma and would made bias to the healing process. Finally, there were 58 subjects who successfully followed the examination until the end of the study.

Overall Study

Reasons for not completing this period:

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.

6. Primary Endpoint

The registry lists the primary outcome as Changes of Levator Hiatal Area During Valsava, measured over Baseline (third trimester), 40 days post-partum, 3 months post-partum.

The primary outcome is titled “Changes of Levator Hiatal Area During Valsava.” The recorded unit is Cm2, and the summary measure is the median with an inter-quartile range. The stated measurement occasions are baseline in the third trimester, 40 days post-partum, and 3 months post-partum. The outcome description refers to changes in lower hiatal area during Valsalva compared with baseline, measured using translabial three-dimensional ultrasound.

The endpoint is intended to quantify anatomy under a specified maneuver. The record explains that, with the translabial technique at an angle of 70 degrees or more, the levator hiatus and surrounding muscles, including pubococcygeus and puborectalis, can be visualized. It also presents ultrasound as potentially more reproducible because axial measurements are easier with minimal dimensional images, whether measurements are made at rest, during Valsalva, or during contraction. This is the registry's rationale for the measurement approach, not evidence in the record that reproducibility was tested or achieved.

In general, a repeated anatomical measure can describe how a structure varies over time, while a comparison between randomized groups can help distinguish group patterns from changes shared over time. The record does not provide the actual medians or inter-quartile ranges, nor a single defined between-group contrast. It therefore does not permit a numerical interpretation of the endpoint or an assessment of precision at any listed time point.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods need to match the question being asked. Here the registry describes an anatomical outcome measured at baseline and at post-partum follow-up, but the record does not identify one comparison as the primary statistical contrast. That limitation prevents a complete account of the analysis. The following concepts explain how such results are generally interpreted; they do not establish which methods were used in this trial.

What does a median and inter-quartile range describe?

The primary outcome is summarized using a median and inter-quartile range. In general, the median is the midpoint of an ordered set of observations: half the values lie at or below it and half at or above it. The inter-quartile range describes the span of the middle portion of the observations. These summaries can be useful when values are skewed or when extreme observations make a mean and standard deviation less representative of a typical value. They describe the distribution within a group; by themselves, they do not quantify a treatment effect or its uncertainty.

Comparing medians can be useful descriptively, but a difference between reported medians is not necessarily the same as a model-based treatment estimate. The statistical interpretation depends on the target contrast, the analysis method, the distribution of measurements, and how repeated observations are handled. No test or model for the primary outcome is reported in the registry record, so it is not possible to say how the trial analyzed the medians or whether the analysis adjusted for baseline.

Why does the choice of comparison matter?

The record lists measurements at baseline in the third trimester, 40 days post-partum, and 3 months post-partum. A within-group change asks how measurements in one group differ over time. A between-group comparison asks whether outcomes differ between randomized groups at a specified point or in their pattern of change. These are different questions. A group can change over time even when the groups do not differ from each other, and a baseline-to-follow-up change does not on its own establish an intervention effect.

For repeated measurements, a statistical analysis may account for the fact that observations from the same participant are related. General approaches include analyzing a prespecified follow-up value with baseline adjustment, modeling repeated measurements jointly, or comparing changes from baseline. Each approach has assumptions and produces an estimate answering a particular question. The registry record does not report which approach, if any, was used. Nor does it state how measurements that were unavailable at follow-up were handled.

How should uncertainty be assessed?

In general, a confidence interval gives a range of values compatible with the observed data and the assumptions of the analysis, and conveys the precision of an estimate. A narrow interval indicates greater precision than a wide interval, while an interval that includes values on both sides of a null difference may leave the direction of the effect uncertain. A p-value addresses compatibility with a specified null hypothesis under an analysis model; it does not measure the size or clinical importance of an effect. The detailed record does not report a primary effect estimate, confidence interval, or p-value, so neither the magnitude nor the precision of the primary comparison can be assessed.

Because the outcome is reported as a median and inter-quartile range, uncertainty should be interpreted in relation to the actual estimator and analysis procedure used. General methods may estimate uncertainty for a median or for a contrast between groups, but the appropriate approach depends on the data and prespecified estimand. No such procedure is identified in the registry record. It would therefore be inappropriate to infer inferential results from summary statistics that are not posted.

What do the planning assumptions mean?

The record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. In general, a sample-size illustration asks how many participants per arm might be required to detect an effect of a specified size under stated assumptions. Varying the assumed fraction of an observed effect can show how planning requirements change when a smaller effect is targeted. These are hypothetical planning scenarios rather than results from the randomized comparison.

The trial's own sample-size justification is not reported in the registry record. The illustration does not establish the trial's original target, and it is not observed power. Observed power is not a useful replacement for interpreting an estimate and its uncertainty after a study is completed. Since the detailed numerical estimates underlying the illustration are not present in the registry entries, no planning values can be interpreted or repeated.

What can be concluded about the analysis plan?

The record does not report the statistical analysis plan, the method used to generate the random sequence, allocation concealment, interim analyses, or a clearly defined analysis population. It also does not report whether the primary outcome was analyzed according to assigned group or among participants with available measurements. These are not details that can be inferred from the labels randomized, triple masking, or completed. They are important because they affect the interpretation of estimates and the possibility of bias.

In general, a well-described analysis specifies the outcome, comparison, time point, population, summary measure, and method for uncertainty before results are examined. For this trial, the posted outcome description establishes the anatomical measurement and its scheduled time points, but not a unique comparison or analysis method. The statistical interpretation must therefore remain limited to what the record explicitly states.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome is recorded across multiple time points, and the registry specifically notes that it was not reduced to one comparison. Multiple analyses can arise when investigators examine several time points, outcome categories, or contrasts. In general, the more comparisons considered, the greater the chance that an apparently notable finding may arise by chance if no suitable inferential strategy is used. Adjustments, a hierarchy of outcomes, or a clearly prespecified primary comparison can help define how results should be interpreted. The registry record does not report a multiplicity strategy, and no correction or testing hierarchy should be assumed.

The record lists two outcome measures and two analyses, but does not describe their full contents or identify how they relate to the primary endpoint. The registry does not specify which time point was designated as the principal inferential comparison, whether the time points were analyzed jointly, or whether conclusions were based on within-group or between-group contrasts. It also does not report an analysis plan that would clarify these decisions.

Missing-data methods are not reported in the registry record. The enrollment entry does not establish the number with a measurement at each time point, and there is no participant-flow information describing withdrawals, unavailable ultrasound assessments, or exclusions. The record does not state whether an analysis used all randomized participants, a subset with observed outcomes, or another population. In general, missing measurements can affect both the precision and validity of a comparison, especially if availability differs by group or relates to the outcome. Without details on completeness and handling, those possibilities cannot be assessed.

Randomization protects the intended comparison when participants are analyzed appropriately, but the registry's design label alone does not establish the analysis population or resolve missing data. The absence of these details limits reproducibility and leaves uncertainty about how the posted summary statements were generated.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry lists serious adverse events among 29 at-risk participants in the intervention group and 29 at-risk participants in the control group. The listed serious-event count is 0 in each group. It also lists other adverse events among 29 at-risk participants in each group, with a count of 0 in both groups, and deaths are recorded as 0 in each group. No top serious-event terms are listed.

These entries describe the safety counts recorded in the registry; they should not be read as proof that no adverse effects were possible. The listed at-risk counts are not the same as the registry's overall enrollment entry, and the record does not explain the relationship between those counts and the full enrollment. It also does not report the duration of safety follow-up, the definitions used for serious and other adverse events, how events were collected, or whether the counts include all participants who received an assigned intervention.

In general, a zero count in a registry entry means that no events of that category were recorded within the stated reporting context. It does not rule out events that were not captured, events outside the observation period, or uncommon risks that the available data could not characterize. These figures are therefore best treated as limited descriptive entries rather than a complete safety assessment or a comparison of risk between groups.

12. What the Result Does, and Does Not, Mean

The trial addresses a relevant statistical question: whether post-partum platelet-rich plasma injection is associated with a different pattern in a measured pelvic-floor anatomical outcome than no platelet-rich plasma intervention. The randomized parallel design is intended to support a comparison between intervention and control groups. The primary endpoint uses translabial three-dimensional ultrasound to assess levator hiatal area during Valsalva, with measurements scheduled at baseline in the third trimester and at post-partum follow-up.

What the detailed registry record does not establish is the numerical result of that comparison. It does not report the group-specific medians or inter-quartile ranges, a defined between-group estimate, confidence interval, or p-value. Therefore, the magnitude, direction, and precision of the primary outcome effect cannot be judged from the posted result details. The brief summary's statements about reduced hiatal area and maintained levator muscle strength do not provide the estimates or analysis needed to evaluate those claims statistically.

The record also does not allow readers to determine whether the reported summary refers to a within-group change, a between-group difference, or a selected time point. Multiple scheduled measurements make that distinction important. Without a prespecified primary contrast and information on multiplicity, missing data, and analysis population, it is not possible to reconstruct the inferential basis for the summary wording.

The safety entries show zero recorded serious adverse events, other adverse events, and deaths in each group among the listed at-risk counts. Those counts are informative as registry entries, but they do not establish the completeness of surveillance or characterize rare or longer-term events.

In general, trial design and outcome definitions describe what investigators intended to compare; outcome estimates and their uncertainty show what the data indicate. The registry provides some design and measurement details, but not the quantitative primary comparison. It therefore supports a description of the study question and its recorded safety counts, not a conclusion about the size or certainty of an intervention effect.

13. Why This Trial Matters Statistically

This trial is statistically notable for combining randomized allocation with an anatomical outcome measured at more than one time point. Such a design can, in principle, distinguish differences between assigned groups from changes that occur over time in both groups. The primary measurement also has a defined modality: translabial three-dimensional ultrasound during Valsalva. The registry explains why the investigators considered this technique useful for visualizing the levator hiatus and surrounding muscles.

The record also illustrates why outcome definitions and comparisons need to be specific. “Change from baseline” can refer to several distinct analyses, and repeated measurements create more than one possible contrast. Without a stated primary comparison, readers cannot know which estimate should carry the main interpretation or how multiple time points were handled. The registry itself notes that the outcome has several categories or time points and was not reduced to one comparison.

Another important statistical issue is the difference between a study result and a planning illustration. The registry describes sample-size illustrations based on the observed effect and specified assumptions. Such calculations can help explore planning scenarios, but they do not replace the trial's own sample-size rationale, which is not reported, and they are not observed power. Clear labeling of these distinctions helps prevent a hypothetical calculation from being mistaken for evidence about the trial's precision.

Finally, the detailed numerical outcome estimates and analysis methods are not reported in the registry record. This limits reproducibility and prevents an independent reading of the treatment contrast. The case underscores that registration details about design and measurement are valuable, but a completed-trial record is most informative when it also reports group results, uncertainty, analysis populations, and the handling of repeated or missing observations.

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 principal limitation for interpretation is the absence of numerical primary outcome results in the registry record. Although the outcome is defined by measure, summary statistic, and time points, group-specific medians and inter-quartile ranges are not reported. No single between-group estimate, confidence interval, or p-value is available. The brief summary gives qualitative statements, but does not define the comparison or quantify its uncertainty.

The primary outcome includes multiple measurement occasions, and the record says it was not reduced to one comparison. The analysis plan, treatment contrast, and approach to repeated observations are not reported. It is consequently unclear how the several time points were interpreted or whether multiplicity was addressed. The record also does not give the details necessary to assess missing measurements, participant flow, or the analysis population.

Some design and procedure details are also absent. The registry does not report the randomization method, allocation concealment, who was masked under the triple-masking label, or how masking was maintained. It does not describe platelet-rich plasma preparation or dose. The protocol's sample-size justification and detailed statistical plan are not reported in the registry record.

The safety counts have their own limits: the observation period, event definitions, and ascertainment procedures are not reported, and the listed at-risk counts do not clarify coverage of the overall enrollment. These omissions restrict interpretation of both efficacy-related outcomes and safety. The trial's completed status does not resolve these reporting gaps.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Platelet Rich Plasma in Levator Ani Muscle Trauma — NCT03021954.
• Registry record last updated 2024-01-29; status last verified 2023-07.
• Results first posted 2024-01-29.
• 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.

18. Record Summary

The registry record describes a completed randomized, parallel-group, triple-masked trial with phase 2 and phase 3 labels and an enrollment of 116. The listed start is 2016-11, and primary completion is 2019-01. The trial concerns platelet-rich plasma injection after labor in the setting of post-partum levator ani muscle trauma.

The intervention was intramuscular platelet-rich plasma injection into pelvic floor muscle immediately following labor and before perineoraphy, alongside local anesthesia. The control group received local anesthesia before perineoraphy without platelet-rich plasma intervention. The primary outcome is change in levator hiatal area during Valsalva, measured by translabial three-dimensional ultrasound and summarized using medians and inter-quartile ranges at baseline in the third trimester, 40 days post-partum, and 3 months post-partum.

Numerical primary outcome results and a single comparison are not reported in the registry record. The safety entries list zero serious adverse events, other adverse events, and deaths in each group among the listed at-risk counts. Analysis details, missing-data handling, and the trial's own sample-size justification are not reported.