Comparing Intra-vaginal Culture of Embryos to In-vitro Culture of Embryos With Minimal Stimulation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparing Intra-vaginal Culture of Embryos to In-vitro Culture of Embryos With Minimal Stimulation (NCT02802176), a randomized na study. The primary outcome is Implantation Rate.

2. Clinical Question

The primary outcome is a transfer-level percentage summarized as a mean across participants. It is not the same as the proportion of participants who became pregnant: the definition counts gestational sacs relative to embryos transferred. The registry also lists embryo quality, fertilization rate, clinical pregnancy rate, and live birth rate as secondary outcomes. The trial was terminated; the reason for termination is not reported in the registry record.

3. Trial Design

This was a randomized, parallel-group clinical trial comparing two embryo-culture approaches in the setting of minimal stimulation. One group used intra-vaginal culture with the INVOcell device, and the other used traditional IVF culture. Both arm descriptions specify 3 day incubation. The registry lists no masking, so the study is recorded as an unmasked comparison. The phase is listed as NA.

The registry reports enrollment of 39 participants and identifies the study status as terminated. The start is recorded as 2016-10, and primary completion as 2022-04-20. The listed sponsor is University of California, San Francisco. The reason the study was terminated is not reported in the registry record, and the original recruitment or stopping circumstances cannot be inferred from the status alone.

The primary outcome analysis included 12 participants in the intra-vaginal culture arm and 13 in the traditional IVF culture arm. The registry states that 2 participants assigned to intra-vaginal culture and 3 assigned to traditional IVF culture were excluded from this analysis because they did not undergo embryo transfer. The safety figures use different group denominators: 14 participants at risk in the intra-vaginal culture arm and 16 in traditional IVF culture. The record does not explain the difference between those safety denominators and the primary analysis groups.

The registry posts arm summaries for the primary outcome and three secondary outcomes, but lists no reported analyses. The original statistical analysis plan, details of randomization implementation, sample-size justification, interim analyses, and handling of missing outcome data are not reported in the registry record. The planning illustrations associated with the posted results are derived from the observed effects and are not evidence of the trial’s original design assumptions.

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: 9 of 39 enrolled participants screen failed out of the study prior to randomization assignment. 6 never moved forward with starting clinical fertility treatment, 1 responded poorly to the minimal stimulation medication protocol that was part of the study design and couldn't proceed with the egg retrieval procedure, 1 was at risk for mild Ovarian Hyperstimulatory Syndrome and 1 voluntarily dropped out of the study prior to randomization due to financial and insurance coverage reasons.

Overall Study

Analysis population for the primary outcome, as defined in the registry: 3 participants in the Traditional IVF culture arm and 2 participants in the intra-vaginal culture arm were excluded from analysis as they did not undergo embryo transfers.

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 Implantation Rate, measured over approximately 4 weeks following randomization. Clinically this is typically done around 6 weeks of gestational age.

The primary endpoint was implantation rate, expressed as a percentage of embryo transfers. The registry defines it as the number of gestational sacs identified on early pregnancy ultrasound divided by the number of embryos transferred. The assessment was planned approximately 4 weeks following randomization, typically around 6 weeks of gestational age.

This endpoint captures implantation at the level of embryos transferred rather than simply classifying each participant as pregnant or not pregnant. In principle, it reflects how often transferred embryos are associated with a gestational sac at the early ultrasound assessment. Because the denominator is embryos transferred, the measure depends on the transfer process as well as the ultrasound assessment. The registry does not report individual participant transfer counts or the underlying gestational-sac counts, so those details cannot be reconstructed from the arm-level means.

The posted primary results summarize this percentage using a mean and standard deviation for each arm. The mean describes the average reported implantation percentage across the analyzed participants; the standard deviation describes how much the individual values varied around that average. These summaries do not by themselves show the distribution of individual results or the number of participants with any gestational sac. The exclusion of participants who did not undergo embryo transfer also means the primary analysis concerns the subset with transfers, rather than every randomized participant.

7. Results Posted in the Registry

• Traditional IVF Culture: mean 42.31 versus 12.50 on control; difference 29.81 (95% CI 6.34 to 53.28), standardized effect d = 0.96; z-test p = 0.013.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Fertilization Rate

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Traditional IVF Culture: mean 63.40 versus 61.75 on control; difference 1.65 (95% CI -18.30 to 21.60), standardized effect d = 0.06; z-test p = 0.871.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Traditional IVF Culture and the control. The interval gives the range of effects that remain compatible with the data.

Clinical Pregnancy Rate

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Traditional IVF Culture: mean 46.15 versus 12.50 on control; difference 33.65 (95% CI 3.58 to 63.72), standardized effect d = 0.86; z-test p = 0.028.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for Traditional IVF Culture than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Live Birth Rate

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Traditional IVF Culture: mean 38.46 versus 12.50 on control; difference 25.96 (95% CI -3.52 to 55.44), standardized effect d = 0.68; z-test p = 0.084.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Traditional IVF Culture and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists embryo quality, fertilization rate, clinical pregnancy rate, and live birth rate as secondary outcomes. It posts arm summaries and recalculated comparisons for fertilization, clinical pregnancy, and live birth. Embryo quality is listed, but its outcome details are not reported in the registry record. Across the posted secondary comparisons, the point estimates do not all have the same degree of separation from zero, and the confidence intervals vary in whether they span zero.

These outcomes help place the primary implantation estimate in a broader sequence of measures: fertilization concerns oocytes, while clinical pregnancy and live birth occur later in the treatment pathway. They are related but not interchangeable endpoints. A difference in one does not automatically imply a difference in another, and the registry does not provide a joint analysis connecting the outcomes at participant level. The secondary results therefore offer context, not a direct explanation for the primary result.

Secondary comparisons carry less weight when their status in the analysis plan, multiplicity handling, and reporting process are unclear. The registry lists no reported analyses and does not report whether the outcomes were prespecified in a detailed statistical plan or whether any adjustment was made for testing several outcomes. When multiple outcomes are examined, some estimates may appear noteworthy by chance even if there is no underlying difference. This is a general reason to interpret unadjusted secondary p-values cautiously, not evidence that any particular result is false.

The primary endpoint remains the central comparison identified by the registry, but it should not be treated as independently confirmed by the secondary endpoints. The secondary estimates are based on small group sizes and have their own uncertainty. Their appropriate role is to describe the pattern of posted outcomes and motivate careful evaluation in a better-documented analysis, rather than to settle the primary question.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Embryo Quality
• Fertilization Rate
• Clinical Pregnancy Rate
• Live Birth Rate

9. Statistical Interpretation

10. Statistical Methods Explained

The primary and secondary continuous outcomes are reported as means with standard deviations. A mean is the arithmetic average of the recorded values; a standard deviation describes the spread of those values around the mean. The reported unit varies by outcome: implantation, clinical pregnancy, and live birth are percentages of embryo transfers, while fertilization rate is a percentage of oocytes fertilized. These percentages are summarized across participants, rather than presented as a single pooled event rate.

What does the mean difference represent?

Each posted comparison gives the difference between the traditional IVF culture mean and the intra-vaginal culture mean. A positive difference therefore indicates a higher mean in the traditional IVF culture arm for that comparison; a negative difference would indicate a higher mean in the intra-vaginal culture arm. For implantation rate, the reported difference is 29.81 percentage points on the stated percentage scale. This is a difference in means, not a relative increase, ratio, or count of additional pregnancies. No such relative measure is reported.

The comparison is accompanied by a 95% confidence interval. In general, a confidence interval describes the range of values reasonably compatible with the data and the statistical method used, while reflecting sampling uncertainty. It is not a guarantee that the true effect lies inside the interval, nor does it describe the range of individual participant outcomes. The registry provides intervals for the recalculated comparisons, but does not report the method used in an original sponsor analysis because no reported analyses are listed.

How should the p-value be understood?

A p-value describes how unusual data at least as incompatible with a specified null hypothesis would be if that null hypothesis and the calculation’s assumptions held. It is not the probability that the null hypothesis is true, nor a measure of clinical importance. The posted p-values are labeled unadjusted. For the primary comparison, p = 0.013. This is a nominal result for the displayed comparison; it does not account for testing multiple outcomes, and the registry does not report a multiplicity adjustment.

The recalculated comparisons are simple, unadjusted re-calculations from the posted summary statistics. They should be distinguished from an analysis reported by the trial investigators. The registry lists no reported analyses, and the original statistical methods are not reported in the registry record. The recalculations do not establish which covariates, if any, were planned for adjustment, how missing observations were handled, or whether another analysis population was prespecified.

Why do variation and distribution matter?

Standard deviations are large relative to some of the mean values, indicating that participant-level percentages varied. In general, when continuous data are bounded percentages, the distribution may not be well described by a symmetric bell-shaped curve, particularly in small samples or when many values lie near a boundary. The registry does not post participant-level data or distributional diagnostics, so the shape of these outcome distributions cannot be evaluated. A mean and standard deviation alone cannot show whether a few extreme values influenced an average.

Over-dispersion is a general concern when observed variation is greater than a chosen statistical model expects. If a model assumes less variation than the data contain, its uncertainty estimates may be too narrow. Conversely, a model that accounts for extra variation can produce more realistic uncertainty. This is a general statistical consideration, not a claim that the trial used a particular model or that over-dispersion was assessed. The registry does not report a model specification or diagnostic results.

What do the standardized effects add?

The posted comparisons also include a standardized effect size, which expresses a mean difference relative to a pooled standard deviation. In general, standardization can help describe the size of a difference in relation to the variability of the measurement. It does not replace the difference on the original percentage scale, and it can be unstable when group sizes are small or variability estimates are imprecise. The standardized value is a summary of the observed data, not a direct measure of clinical importance.

The values for each arm, the mean differences, confidence intervals, and p-values should be read together. The means show the direction and scale of the estimates; standard deviations describe observed spread; intervals express uncertainty around comparisons; and p-values summarize compatibility with a null comparison under the calculation’s assumptions. None of these components supplies missing details about trial conduct or turns a small, unadjusted comparison into a definitive result.

11. Confidence Intervals and Precision

Precision is about how narrowly an estimate is pinned down by the data and method. For implantation rate, the mean difference comparing traditional IVF culture with intra-vaginal culture is 29.81, and its 95% confidence interval runs from 6.342 to 53.28. The interval is wide enough that the exact size of the difference remains uncertain, even though the interval does not include zero. It is the range of uncertainty around the estimated group difference, not a range containing most individual participants’ outcomes.

The primary analysis includes 12 participants in one arm and 13 in the other. Small group sizes generally limit precision, and the posted standard deviations show appreciable variability, particularly in the traditional IVF culture arm. The mean difference therefore should not be treated as a precisely known constant. The interval gives more information than the point estimate alone, but it depends on the statistical calculation and its assumptions.

The secondary intervals illustrate why a point estimate and its uncertainty need to be considered together. The fertilization-rate interval extends across negative and positive differences, as does the live-birth interval. The clinical-pregnancy interval is entirely positive in the posted unadjusted comparison, but it is also broad. The registry does not report adjusted intervals or a multiplicity procedure, so the posted intervals do not address the uncertainty associated with examining several outcomes.

Confidence intervals also do not correct for selection into the analyzed group. The primary analysis excludes participants without embryo transfers, and the registry does not report a separate analysis including all randomized participants or an analysis of missing outcome data. The intervals describe statistical uncertainty for the posted comparisons; they cannot resolve uncertainty about how the analyzed participants represent all randomized participants or future populations.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size figures are planning illustrations based on observed effects, not the trial’s original design calculations. For these continuous outcomes, the figures are participants per arm, not total events. The registry’s planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each row considers an effect to detect equal to a stated fraction of the observed effect. The original trial’s sample-size justification and design assumptions are not reported in the registry record.

The 80% power column gives the illustrative number of participants per arm for a design with an 80% chance of detecting the specified effect under the planning assumptions, if that effect and the assumptions were correct. The 90% power column describes the corresponding planning target with a 90% chance. Power is a property of a proposed design under specified assumptions; it is not a probability that the observed result is true.

The rows scale the target effect to 100%, 75%, or 50% of the observed effect. Smaller effects are harder to distinguish from random variation, so planning for a smaller effect requires more participants. The figures should be interpreted as sensitivity illustrations: the required group size changes when the assumed effect changes. They do not show that the trial enrolled enough participants for its original objective, because its own design assumptions are not reported.

This is not observed power. It is a forward-looking calculation using the observed effect as its starting point, and it should not be used to explain the p-value or to judge whether the trial’s design was adequate.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 29.810; pooled standard deviation σ = 31.183.
2. n = 2 × (1.96 + 0.842)² × 31.183² / 29.810² = 17.2, rounded up to 18 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 29.81                      # observed difference in means
sigma <- 31.183022849928                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(2802176)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 18 (80% power), 23 (90% power)
 75% of observed effect: n per arm = 31 (80% power), 41 (90% power)
 50% of observed effect: n per arm = 69 (80% power), 92 (90% power)
power.t.test: 18.2 
Simulated power at n = 18 per arm: 0.791 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when statistical tests are conducted for several outcomes, comparisons, or analysis choices. Even when each test uses a conventional threshold, examining multiple results increases the chance that at least one will appear unusual by chance. Statistical approaches can address this, for example by adjusting thresholds or controlling a family-wise error rate, but the choice depends on the analysis plan and scientific question. This is general statistical context, not a description of a method used in this trial.

The registry lists one primary outcome and several secondary outcomes, and the posted comparisons carry unadjusted p-values. No multiplicity adjustment is reported in the registry record. The registry also lists no reported analyses. Consequently, the posted p-values should be read as unadjusted comparisons rather than as family-wise error controlled evidence across the set of outcomes. It is not reported whether any outcome hierarchy, gatekeeping strategy, or other multiplicity procedure was prespecified.

Missing-data handling is also not reported in the registry record. The primary outcome population excludes 3 participants in the Traditional IVF culture arm and 2 in the intra-vaginal culture arm because they did not undergo embryo transfers. That is an explicit exclusion criterion for the posted primary analysis, but the record does not explain whether those participants were excluded from other outcome analyses, how any other missing observations were treated, or whether sensitivity analyses were conducted. The outcome definition requires embryo transfers, so the estimand represented by the primary summary is among participants who underwent transfers, rather than a result for every randomized participant.

The registry does not report an intention-to-treat analysis, a per-protocol analysis, a missing-data model, or reasons for missing outcomes beyond the stated absence of embryo transfer. It is therefore not possible to assess whether the posted estimates depend on particular assumptions about unobserved outcomes. These omissions do not establish that the analysis was inappropriate; they limit what can be concluded about its prespecification and robustness.

Allocation is recorded as randomized, but details of sequence generation, allocation concealment, and implementation are not reported. Interim analyses and stopping rules are also not reported. Because the study status is terminated, the reason and its relation, if any, to recruitment, operations, or results cannot be inferred from the registry entry.

15. 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 reports serious adverse events, other adverse events, and deaths separately for the two arms. For the intra-vaginal culture arm, 14 participants were listed as at risk, with 0 serious adverse events, 0 other adverse events, and 0 deaths. For traditional IVF culture, 16 participants were listed as at risk, with 0 serious adverse events, 0 other adverse events, and 0 deaths.

These figures mean that no events in those categories were recorded in the posted safety summaries during the registry’s reporting period. They do not establish that the underlying risk is zero, particularly in groups of this size. A zero count in a small sample leaves considerable uncertainty about events that could occur in a larger population or over a different observation period. The registry does not provide additional event detail, definitions, or follow-up duration for these safety counts.

The safety denominators differ from the primary outcome analysis groups. The record does not explain that difference. The absence of reported events should be interpreted as a description of the posted counts, not as a comprehensive comparison of safety or as evidence that either approach is free of adverse events.

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

The posted primary comparison estimates a higher mean implantation rate in the traditional IVF culture arm than in the intra-vaginal culture arm among participants included in the analysis. The estimated difference is 29.81, with a 95% confidence interval from 6.342 to 53.28 and an unadjusted p-value of 0.013. These statistics describe the observed comparison and its sampling uncertainty under the calculation used; they do not establish a definitive or universal treatment effect.

The endpoint is a percentage of embryos transferred, based on gestational sacs seen at early ultrasound, rather than a participant-level yes-or-no pregnancy measure. The analysis excludes participants who did not undergo embryo transfer. The interpretation therefore applies to the analyzed transfer population and should not be silently extended to all enrolled or randomized participants. The registry does not provide individual data or enough detail to examine alternative populations.

The result does not prove that one culture method causes a better outcome in every clinical setting. Randomization supports a comparative design, but the registry record does not report enough information about implementation, analysis choices, or missing data to evaluate all sources of bias. The sample is small, variability is substantial, and the estimated difference has an interval wide enough to leave uncertainty about its magnitude.

The secondary endpoints do not turn the primary estimate into a complete account of the trial. Their comparisons are also based on limited groups, and the registry does not report multiplicity handling. The safety counts are zero in the posted categories, but small denominators cannot exclude uncommon events. Nor does the terminated status, by itself, reveal why the study ended or what conclusions its investigators intended.

Accordingly, the most defensible reading is narrow: the registry’s unadjusted primary comparison favors a higher observed mean for traditional IVF culture in the analyzed participants, while the precise size and broader applicability of that difference remain uncertain. The results should be understood as statistical evidence from this trial record, not as medical advice or a recommendation about treatment.

17. Why This Trial Matters Statistically

This trial illustrates why the definition of an endpoint and its analysis population matter. Implantation rate is defined using gestational sacs per embryos transferred, so it is not a simple participant-level pregnancy proportion. Participants who did not reach embryo transfer were excluded from the primary analysis. That choice shapes the population to which the posted estimate directly applies and highlights the distinction between randomized participants and those contributing a particular outcome.

The results also show why an estimate should be read alongside its uncertainty. A difference of 29.81 is a clear point estimate on the registry’s percentage scale, but the confidence interval from 6.342 to 53.28 indicates that the magnitude is not precisely determined. Variation within the arms and small analyzed groups constrain how confidently the exact size can be generalized. A p-value alone would not convey this uncertainty or the outcome’s scale.

Another statistical lesson is that a collection of outcomes needs an analysis strategy. The registry lists one primary endpoint and multiple secondary outcomes, but no reported analyses or multiplicity procedure. Without those details, the posted secondary comparisons are best viewed as descriptive and exploratory. A nominal result across several outcomes should not be interpreted as if it were the sole prespecified test.

Finally, registry transparency matters for interpretation. The record makes the group summaries, exclusions, and safety counts available, but does not report the original sample-size justification, detailed statistical plan, interim analyses, or reasons for termination. Those gaps do not erase the numerical findings; they define the limits on how fully their robustness and intended context can be assessed.

18. 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 analysis is small and excludes participants who did not undergo embryo transfer: 2 from the intra-vaginal culture arm and 3 from traditional IVF culture. This makes the result specific to the analyzed participants who underwent transfer. The registry does not report a complementary analysis using all randomized participants, so the effect of this exclusion on the comparison cannot be assessed.

The primary endpoint is a mean percentage with a standard deviation, but the record does not provide participant-level observations, embryo counts, or distributional diagnostics. The influence of unusually high or low observations cannot be checked. The mean and standard deviation may not fully describe a bounded percentage measure, especially with small groups, and no alternative summary is reported.

There is limited detail about trial conduct and analysis. Randomization and lack of masking are recorded, but the methods used to generate and implement allocation are not reported. The original statistical analysis plan, sample-size justification, interim analyses, handling of missing data, and multiplicity strategy are not reported in the registry record. The registry lists no reported analyses, so the displayed comparisons cannot be compared with a detailed prespecified analysis.

The trial is marked terminated, but the reason is not reported in the registry record. Without that context, the status cannot be connected to the observed outcomes or used to infer why enrollment ended. The safety denominators also differ from the primary analysis groups, and the record does not explain the difference. Finally, only three of the four listed secondary outcomes have posted numerical results; embryo quality details are not reported. These limitations constrain interpretation without changing the values in the registry summaries.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Comparing Intra-vaginal Culture of Embryos to In-vitro Culture of Embryos With Minimal Stimulation — NCT02802176.
• Registry record last updated 2023-07-12; status last verified 2023-06.
• Results first posted 2023-07-12.
• 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.

22. Record Summary

The registry describes a randomized, parallel-group comparison of 3 day intra-vaginal embryo culture with INVOcell and 3 day traditional IVF culture under minimal stimulation. It lists 39 participants enrolled, no masking, and a terminated status. The primary outcome was implantation rate, defined as gestational sacs seen on early ultrasound divided by embryos transferred.

The primary analysis excluded participants who did not undergo embryo transfer and compared 12 participants in the intra-vaginal culture arm with 13 in traditional IVF culture. The posted mean difference was 29.81 in favor of a higher mean in the traditional IVF culture arm, with a 95% confidence interval from 6.342 to 53.28 and an unadjusted p-value of 0.013. The estimate is uncertain and applies to the analyzed group.

Three secondary outcomes have posted numerical summaries; embryo quality is listed without outcome details. Safety summaries record 0 serious adverse events, 0 other adverse events, and 0 deaths in each arm. The original design assumptions, detailed statistical plan, multiplicity handling, and reason for termination are not reported in the registry record.