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 Effect of Ejaculatory Abstinence on Semen Parameters in Male Factor Infertility Patients (NCT04206800), a randomized na study. The primary outcome is Total Motile Sperm (Million).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04206800 |
| Phase | NA |
| Condition | Infertility, Male |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 5 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Boston IVF |
| Results posted | Yes |
2. Clinical Question
Population
Men with male factor infertility whose partners were scheduled for oocyte retrieval as part of IVF/ICSI. The registry reports enrollment of 5 and describes the primary measure as a change from each participant’s baseline semen analysis to the semen analysis on the day of retrieval.
Intervention
Ejaculatory abstinence less than 24 hours before the scheduled oocyte retrieval. The arm description says men would ejaculate within 24 hours of retrieval.
Comparator
Routine care, described as abstaining from ejaculation greater than 48 hours before providing a semen sample on the day of retrieval. The record also describes routine practice as abstinence from 2 to 5 days before retrieval.
Primary question
Does the change in total motile sperm differ between the routine-care arm and the arm with abstinence less than 24 hours? The posted results give mean values and standard deviations within each arm, but the registry record does not report an inferential comparison between arms.
The study’s question concerns a semen parameter measured around IVF/ICSI treatment, rather than a direct comparison of pregnancy or birth outcomes as the primary endpoint. The registry lists live birth rate, fertilization rate, embryo development, clinical pregnancy rate, miscarriage rate, ongoing pregnancy rate, semen analysis, and preimplantation genetic testing as secondary outcomes. Results for those outcomes are not included in the posted arm summaries described for the primary endpoint.
The trial’s stated hypothesis was that total motile sperm count would improve with abstinence less than 24 hours. A hypothesis is not itself evidence of an effect. Interpreting the results requires distinguishing the group-level descriptive summaries from a formal estimate of the difference between randomized arms, which is not reported in the registry record.
3. Trial Design
The registry describes a randomized, parallel-group study with no masking. Its title identifies the subject as the effect of ejaculatory abstinence on semen parameters in male factor infertility patients. The trial is recorded as terminated, with enrollment of 5. The record names Boston IVF as sponsor and gives a start date of 2020-01-20 and a primary completion date of 2020-07-15. The phase is recorded as NA.
Participants were assigned to routine care or ejaculatory abstinence less than 24 hours. In the routine-care arm, the registry describes abstinence greater than 48 hours before the semen sample on retrieval day, and also describes routine practice as 2 to 5 days of abstinence before scheduled retrieval. In the other arm, men were to ejaculate within 24 hours of retrieval. The record does not report the randomization method or allocation concealment.
The posted primary outcome is total motile sperm, measured in million sperm. The registry describes its calculation as semen volume multiplied by concentration and motility. It defines the endpoint as the difference between a baseline semen analysis, described as a previous analysis before IVF treatment, and the semen analysis on the day of egg retrieval. The stated timeframe is change in baseline and 1-5 months.
Arm-level summaries are reported for 4 participants in Routine Care and 1 participant in the abstinence-less-than-24-hours arm. The registry lists 9 outcome measures and names 8 secondary outcomes. It reports no posted analyses. Details of the intended statistical analysis plan, including the analysis population and handling of protocol deviations, are not reported in the registry record. The reason for termination is 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 | Routine Care | Ejaculatory Abstinence Less Than 24 Hours |
|---|---|---|
| STARTED | 4 | 1 |
| COMPLETED | 4 | 1 |
| NOT COMPLETED | 0 | 0 |
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 | Routine Care | Ejaculatory Abstinence Less Than 24 Hours | Total |
|---|---|---|---|---|
| Participants analysed | 4 | 1 | 5 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 4 | 1 | 5 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Age, Continuous | years | 36 (SD 2.74) | 32 (SD 0) | 35.2 (SD 2.93) |
| Sex: Female, Male: Female | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Male | Participants | 4 | 1 | 5 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Region of Enrollment: United States | participants | 4 | 1 | 5 |
6. Primary Endpoint
The registry lists the primary outcome as Total Motile Sperm (Million), measured over Change in baseline and 1-5 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | million sperm |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is total motile sperm, expressed in million sperm. The registry describes total motile sperm as a semen measure calculated by multiplying volume, concentration, and motility. This combines information about the amount of semen, sperm concentration, and the proportion that are motile into a single measure.
The endpoint is not presented as the retrieval-day value alone. The registry defines it as a change from a participant’s baseline semen analysis, described as a previous analysis before IVF treatment, to the semen analysis on the day of egg retrieval. Its timeframe is recorded as change in baseline and 1-5 months. The record says that the calculated mean can be interpreted as a decrease or change from baseline to the retrieval-day assessment. It does not describe the sign convention in enough detail to establish from the reported values alone whether a positive number means an increase or a decrease.
A semen parameter can be used to characterize sperm available for the IVF/ICSI procedure. It is a laboratory measure, not a direct measure of pregnancy or live birth. The registry separately lists reproductive outcomes, including fertilization, pregnancy, miscarriage, and live birth, as secondary outcomes. Their inclusion does not make them part of the primary endpoint.
For Routine Care, the posted mean is 14.86 million sperm, with a standard deviation of 24.99. For ejaculatory abstinence less than 24 hours, the posted mean is 7.94 million sperm, with a standard deviation of 0.0. These are arm-level descriptive summaries. The registry record does not report a confidence interval or a formal test for the between-arm difference.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary results are descriptive summaries of change in total motile sperm. Routine Care has a reported mean of 14.86 million sperm and standard deviation of 24.99 among 4 participants. The ejaculatory-abstinence-less-than-24-hours arm has a reported mean of 7.94 million sperm and standard deviation of 0.0 among 1 participant. The endpoint is defined as a change from baseline to the retrieval-day semen analysis.
These summaries do not establish whether the arms differ beyond what could arise from sampling variation. The registry record reports 0 analyses and identifies values as missing or not estimable for a two-arm comparison of this continuous endpoint. It therefore provides no inferential estimate of the between-arm effect, confidence interval, or p-value. Without those results, the arm means should not be read as a test of the trial’s hypothesis.
The precision of the summaries is limited by the small and uneven arm sizes reported in the registry. The standard deviation of 0.0 in the abstinence-less-than-24-hours arm is based on a single participant; it cannot characterize variation among participants in that arm. The larger standard deviation reported for Routine Care indicates substantial spread in that arm’s observed values relative to its mean, but the registry record does not provide the participant-level data needed to assess the distribution or identify the source of that variability.
The numerical values also need to be read with the endpoint definition in mind. The registry describes the measure as a difference from baseline and says the mean can be interpreted as a decrease or change. It does not make the direction convention explicit enough to infer an increase or decrease from the positive values alone. Accordingly, the means are best described as the posted values for the recorded change measure, without assigning a direction beyond the registry’s wording.
The trial was terminated, but the reason for termination is not reported in the registry record. The record also does not describe whether recruitment stopped early, whether the planned enrollment was reached, or whether termination was related to the observed semen results. Those circumstances should not be inferred from the status alone.
Overall, the posted data document the arm-specific summaries but do not quantify a comparative treatment effect or its uncertainty. They also do not establish effects on the secondary reproductive outcomes. The results therefore describe the limited observations recorded for the primary measure; they are not a conclusive estimate of what would happen in a larger population of similar patients.
9. Statistical Methods Explained
The primary measure is continuous: it is recorded on a numerical scale in million sperm. The registry identifies the summary measure as the mean and its dispersion as the standard deviation. These statistics describe the observed values within each arm. They do not, by themselves, answer whether assignment to one arm rather than the other is associated with a difference.
What does the mean describe?
A mean is the arithmetic average of the observed measurements in a group. In this study, the reported means summarize the recorded change in total motile sperm from baseline to the semen analysis on retrieval day. A mean is sensitive to unusually high or low observations. That matters particularly when a group has few observations, because an individual value can have a strong influence on the group summary.
The reported means are 14.86 million sperm for Routine Care and 7.94 million sperm for ejaculatory abstinence less than 24 hours. These are not a mean difference between arms. The registry record does not report a calculated between-arm estimate, so a comparison should not be inferred by subtracting one group mean from the other.
What does the standard deviation describe?
The standard deviation describes how dispersed individual observations are around their group mean. A larger standard deviation indicates greater observed variation. It is not a confidence interval and does not describe the precision of an estimate in the same way that a confidence interval does. Routine Care has a reported standard deviation of 24.99. The other arm has a reported standard deviation of 0.0, but its reported group size is 1. A single observation cannot provide an informative estimate of between-participant variability, so the zero should not be interpreted as evidence that the endpoint has no variation in that population.
Why is a between-arm estimate important?
Randomization is intended to support comparison of outcomes between assigned groups. An analysis would ordinarily estimate the difference between arms and characterize its uncertainty. A confidence interval is a range of values compatible with the data under the analysis assumptions; it conveys both the estimated effect and its precision. A p-value, when used, describes how compatible the observed data are with a specified null hypothesis under a statistical model. Neither quantity is reported for this primary comparison in the registry record. No inferential conclusion can be recovered from the arm summaries alone without making additional assumptions or calculations.
The registry explicitly marks the continuous two-arm comparison as having values missing or not estimable. It reports 0 analyses. This means the available record does not contain the sponsor’s comparative analysis for the endpoint. The discrepancy indicator is false, so there is no reported conflict between a sponsor analysis and a recalculated estimate. In any case, no recalculated comparison is posted for this endpoint.
What is over-dispersion, in general?
In general, over-dispersion means that observed variability is greater than a statistical model expects. It can make standard errors and confidence intervals too small if the model does not allow for the extra variability. It is a general statistical concern, not a finding established by this registry record. The arm summaries alone do not permit a reliable assessment of whether a particular model would fit the participant-level measurements.
How should planning illustrations be read?
In general, sample-size planning uses assumptions about the effect to detect, variability, allocation, significance level, and the statistical method. A planning illustration based on the observed effect is not an observed power calculation and is not a measure of the chance that this trial detected an effect. The registry’s stated planning assumptions specify a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For non-time-to-event outcomes, such illustrations are expressed as participants per arm for 80% power or another stated power level. These are planning concepts, not findings from the trial.
For this comparison, the registry indicates that values are missing or not estimable for a two-arm continuous-endpoint analysis. Consequently, a usable observed effect for an illustration is not reported in the registry record. No sample-size requirement for a future study should be inferred from the arm means alone. A planning exercise would need a defensible effect and variability assumption, and those inputs are not established by the posted summaries.
The registry does not report whether the intended analysis would adjust for baseline total motile sperm, other covariates, or the small difference in group sizes. It also does not report assumptions about the distribution of the change measure. Those choices can affect estimates and uncertainty, especially with limited data. They should be treated as unknown rather than reconstructed from the outcome summaries.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 8 secondary outcomes: live birth rate, fertilization rate, embryo development, clinical pregnancy rate, miscarriage rate, ongoing pregnancy rate, semen analysis, and preimplantation genetic testing. It reports 9 outcome measures overall. The record does not report analyses for these secondary outcomes or specify a statistical plan for interpreting multiple outcomes. It is therefore not reported in the registry record whether any adjustment for multiple comparisons was planned or performed.
Multiplicity matters when many outcomes or comparisons are examined. In general, the more statistical tests considered, the greater the chance that at least one result may appear noteworthy by chance if each is interpreted separately. A prespecified hierarchy or adjustment procedure can address this issue, but none is described in the registry record. No claim about statistical significance for secondary outcomes is supported by the posted information.
The record does not report how missing observations were handled, whether any participants were excluded from the primary analysis, or the definition of the analysis population. It gives arm sizes and descriptive values, but not participant-level completeness, reasons for missing measurements, or an imputation method. It is not reported in the registry record whether the primary analysis followed randomized assignment regardless of adherence or used another approach.
These omissions matter because analysis choices can influence both the estimated effect and its uncertainty. With the available summaries, it is not possible to determine whether the reported participants represent all randomized participants for the endpoint or whether missing outcome data affected the comparison. No assumptions about those procedures should be filled in from customary practice.
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 |
|---|---|---|---|
| Routine Care | 0 | 4 | 0.0% |
| Ejaculatory Abstinence Less Than 24 Hours | 0 | 1 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Routine Care | 0 of 4 |
| Ejaculatory Abstinence Less Than 24 Hours | 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 |
|---|---|
| Routine Care | 0 of 4 |
| Ejaculatory Abstinence Less Than 24 Hours | 0 of 1 |
The registry reports serious adverse event counts of 0 among 4 at risk in Routine Care and 0 among 1 at risk in the ejaculatory-abstinence-less-than-24-hours arm. It also reports other adverse event counts of 0 among 4 at risk and 0 among 1 at risk, respectively. Deaths are recorded as 0 in both arms. No serious adverse event terms are listed.
These are event counts for the participants represented in the registry record. They do not establish that the procedures have no risks or that an adverse event could not occur in a larger group. The arm sizes are limited, particularly in the abstinence-less-than-24-hours arm, so the absence of recorded events offers little information about uncommon events.
The record does not provide additional detail on adverse-event definitions, collection procedures, observation duration, severity grading, or relatedness. It also does not report a comparative safety analysis. The counts should therefore be read as the events recorded in the registry, not as a complete characterization of safety or as evidence that the arms have equivalent safety profiles.
12. What the Result Does, and Does Not, Mean
The registry records a randomized comparison of routine ejaculatory abstinence and abstinence less than 24 hours before oocyte retrieval, with change in total motile sperm as the primary outcome. It posts an arm mean of 14.86 million sperm for Routine Care and 7.94 million sperm for the abstinence-less-than-24-hours arm. These summaries describe the recorded values in the participants represented for each arm.
The posted results do not establish that one abstinence approach produces a larger or smaller change. No inferential comparison, confidence interval, or p-value is reported, and the registry flags the two-arm continuous comparison as missing or not estimable. In addition, the endpoint’s direction convention is not fully explicit in the record. The values should not be interpreted as proof of an effect or lack of effect.
The study’s stated hypothesis concerned improved total motile sperm with abstinence less than 24 hours. A hypothesis is a question to be tested, not a conclusion. The descriptive means do not resolve that question, particularly given the reported group sizes of 4 and 1 and the lack of a between-arm analysis. The standard deviation of 0.0 in the smaller arm does not demonstrate absence of variability; it reflects a group with a single reported participant.
The primary endpoint is a semen measure, not a pregnancy or live-birth outcome. Although the registry names reproductive outcomes as secondary outcomes, their results are not reported in the posted record. Therefore, the primary summaries cannot be used to draw conclusions about fertilization, pregnancy, miscarriage, ongoing pregnancy, or live birth.
The trial status is terminated, but the registry does not report why. The status alone does not show whether termination was related to safety, feasibility, results, or another reason. The results are best understood as a limited set of descriptive observations rather than a definitive comparative assessment.
13. Why This Trial Matters Statistically
This trial raises a focused statistical question: whether changing the timing of ejaculation before egg retrieval is associated with a change in a semen parameter used in IVF/ICSI. The randomized parallel design is relevant because randomized assignment can support a comparison between groups, provided that outcomes are collected and analyzed in a way that preserves the intended comparison.
The registry also illustrates why design labels and outcome summaries are not enough to evaluate evidence. Although the trial is described as randomized, the posted primary results contain only arm-specific means and standard deviations. A reader needs a comparative estimate and its uncertainty to assess the evidence for a difference. The registry reports no analyses and flags the two-arm comparison as missing or not estimable.
The group sizes are important to interpretation. The reported size of the abstinence-less-than-24-hours arm is 1, so its mean reflects a single observation and its standard deviation cannot represent participant-to-participant variation. The Routine Care summary is based on 4 participants and has a standard deviation of 24.99. This makes the descriptive summaries especially limited as a basis for general conclusions.
The trial’s status as terminated is another reason to distinguish what is documented from what is unknown. The reason for termination and the intended statistical plan are not reported in the registry record. Neither should be inferred from the outcome summaries or status label.
Statistically, the record is useful for showing how a clinically motivated hypothesis can remain unresolved when comparative analyses and uncertainty estimates are unavailable. It also underscores that a biomarker-like or laboratory endpoint is distinct from patient-centered outcomes such as pregnancy and live birth. Those outcomes are listed as secondary measures, but their results are not included in the posted summaries.
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 primary limitation is the small number of participants represented in the arm summaries: 4 in Routine Care and 1 in the abstinence-less-than-24-hours arm. The mean in the latter arm is therefore based on a single observation, and its reported standard deviation of 0.0 cannot estimate variation across participants. The posted summaries offer limited information about the range or distribution of values.
The registry does not report a formal comparison between arms for the primary endpoint. It marks the values as missing or not estimable for a two-arm continuous comparison and reports 0 analyses. There is no posted between-arm estimate, confidence interval, or p-value. The record also does not report participant-level data that would allow independent assessment of distributions, outliers, or missing observations.
The endpoint is described as change from baseline to the retrieval-day semen analysis, but the direction convention is not fully clear from the record. The timeframe is recorded as change in baseline and 1-5 months. The primary completion date is reported, but additional detail on the timing of each participant’s measurements is not available in the registry record.
The trial is terminated, and the reason is not reported. The record does not describe the planned enrollment target, why enrollment ended, or whether termination affected the completeness of outcomes. It also does not report the randomization procedure, allocation concealment, adherence, missing-data methods, analysis population, or statistical analysis plan.
Although multiple secondary outcomes are listed, results are not reported for them in the posted arm summaries. The registry does not describe any multiplicity strategy. These gaps limit interpretation of both the primary endpoint and the broader set of clinical outcomes, and they prevent conclusions about effects beyond the recorded descriptive values.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effect of Ejaculatory Abstinence on Semen Parameters in Male Factor Infertility Patients — NCT04206800.
- Registry record last updated 2020-09-25; status last verified 2020-09.
- Results first posted 2020-09-25.
- 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
NCT04206800 is a randomized, unmasked, parallel-group study sponsored by Boston IVF, titled Effect of Ejaculatory Abstinence on Semen Parameters in Male Factor Infertility Patients. It is recorded as terminated, with enrollment of 5. The start date is 2020-01-20, and the primary completion date is 2020-07-15. The phase is listed as NA.
The comparison was routine care, involving abstinence greater than 48 hours before the retrieval-day sample, versus ejaculatory abstinence less than 24 hours. The primary endpoint was change in total motile sperm from baseline to the retrieval-day semen analysis. The record posts means of 14.86 million sperm for Routine Care and 7.94 million sperm for the less-than-24-hours arm, with standard deviations of 24.99 and 0.0, respectively.
No inferential primary comparison is reported; the registry marks the continuous two-arm comparison as missing or not estimable. The reason for termination, statistical analysis plan, missing-data procedures, and results for the listed secondary outcomes are not reported in the registry record.