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 Lipid Metabolism in Gestational Diabetes (NCT00534105), a registered phase not stated study. The primary outcome is Cholesterol.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00534105 |
| Phase | Phase not stated |
| Condition | Gestational Diabetes, Hyperlipidemia |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 106 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Baystate Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
Pregnant women scheduled for a three hour glucose tolerance test were invited to enroll. The registry record describes women diagnosed with gestational diabetes and normal pregnant women without gestational diabetes. It reports enrollment of 106, while the study summary describes a planned comparison of 46 women in each group.
Intervention
This was an observational cohort study, not a treatment trial. The study summary describes lipid panels, including total cholesterol, triglycerides, HDL and LDL, collected with a fasting glucose sample and again at the third hour sample. Umbilical cord blood was also to be collected for newborn lipid profiles.
Comparator
The groups were women with an abnormal three hour glucose tolerance test and women with a normal three hour test. The registry record does not state how group assignment was handled beyond diagnosis based on the test. This is not a randomized comparison, and the arms are not a like-for-like control comparison.
Primary question
The stated primary outcome is cholesterol measured at least 6 weeks postpartum in the gestational diabetic group and normal controls. The broader study question was whether women with gestational diabetes have an exaggerated lipid response during pregnancy compared with women without gestational diabetes. The registry record does not report the postpartum cholesterol values or a comparison estimate.
3. Trial Design
The record describes a prospective cohort study of lipid metabolism in pregnancy, with gestational diabetes as the basis for comparing groups rather than a randomized intervention. The study is marked completed, and Baystate Medical Center is listed as sponsor. The record lists a start date of 2007-09 and primary completion in 2010-11.
As described in the study summary, routine prenatal care included a one hour glucose challenge test. Women with elevated results then underwent a three hour glucose tolerance test, which was used to diagnose gestational diabetes. Women scheduled for that diagnostic test were to be identified and asked to enroll. The summary proposed comparing 46 women with a normal three hour test with 46 women whose result was abnormal. The registry reports total enrollment of 106; it does not explain the relationship between that enrollment and the proposed group counts.
The planned measurements included total cholesterol, triglycerides, HDL and LDL at the fasting glucose sample and at the third hour sample. The summary also describes umbilical cord blood collection for newborn lipid profiles. The primary outcome record focuses on maternal cholesterol postpartum, with values obtained at least 6 weeks after delivery. The listed secondary outcomes are triglyceride values, HDL and LDL.
The study summary is incomplete in the registry record, ending during its description of the study procedures. Additional protocol details, including recruitment procedures, follow-up completeness, and the exact analysis populations, are not reported in the registry record. The allocation approach is not stated, and the registry explicitly cautions that the arms are not a like-for-like control comparison.
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: Only uncomplicated obstetrical patients
Overall Study
| Stage | Gestational Diabetics | Normal Pregnancies |
|---|---|---|
| STARTED | 47 | 59 |
| COMPLETED | 24 | 20 |
| NOT COMPLETED | 23 | 39 |
Reasons for not completing this period:
| Reason | Gestational Diabetics | Normal Pregnancies |
|---|---|---|
| Lost to Follow-up | 23 | 39 |
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 | Gestational Diabetics | Normal Pregnancies | Total |
|---|---|---|---|---|
| Participants analysed | 47 | 59 | 106 | |
| Age Continuous: Age at Recruitment | years | 32 (30 to 36) | 30 (26 to 34) | 31 (28 to 35) |
| Sex: Female, Male: Female | Participants | 47 | 59 | 106 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 47 | 59 | 106 |
6. Primary Endpoint
The registry lists the primary outcome as Cholesterol, measured over Postpartum.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Inter-Quartile Range |
| Unit | mg/dl |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is cholesterol, measured in mg/dl postpartum. The record says values were obtained at least 6 weeks postpartum from the gestational diabetic group and the normal controls. It identifies the outcome measure as a mean and describes dispersion using an inter-quartile range.
These summaries address different aspects of the observed values. The mean describes the arithmetic average, while the inter-quartile range describes the spread of the middle portion of the observations. Reporting both can help readers understand the central level and variability, although neither by itself shows how precisely a difference between groups has been estimated. A confidence interval, if reported, would convey uncertainty around an estimated quantity; no confidence interval or group-specific cholesterol value is reported in the registry record.
The study summary situates postpartum lipid assessment within a broader interest in lipid response during pregnancy and possible postpartum risk. The registry record does not state a more detailed rationale for selecting postpartum cholesterol as the primary endpoint, nor does it report a threshold defining a clinically meaningful difference. It also does not provide the timing of postpartum measurements beyond the statement that they were obtained at least 6 weeks after delivery.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a primary postpartum cholesterol outcome and several additional lipid outcomes, but it contains no reported analyses. It therefore does not provide group means, inter-quartile ranges, an estimated between-group difference, a confidence interval, or a p-value. Without those results, the size and precision of any observed group contrast cannot be assessed from this record.
The enrollment count is 106. The study summary describes a proposed comparison of 46 women in each group, whereas the safety record lists 47 participants at risk in the gestational diabetic group and 59 in the normal pregnancies group. These counts serve different purposes in the record, and no explanation is given for how they relate to the outcome analysis population. They should not be treated as interchangeable denominators.
The design is observational: group membership follows the glucose tolerance test result, rather than random assignment. General statistical interpretation of cohort comparisons must account for the possibility that groups differ in other characteristics. The registry does not report covariate-adjusted analyses or enough detail to assess whether such differences were measured or addressed. Consequently, even if a group difference had been reported, the design alone would not establish that gestational diabetes caused it.
Precision also cannot be judged without estimates and uncertainty measures. General statistical explanation: a confidence interval gives a range of values compatible with the data under the stated model and indicates how uncertain an estimate is. A point estimate without an interval can conceal substantial uncertainty; here, neither is reported. The record likewise provides no information on distributions, missing outcome values, or sensitivity analyses.
The registry lists four outcome measures and zero recorded analyses. This means the record does not furnish a statistical result for the primary endpoint or secondary lipid measures. It does not establish that no analyses were performed outside the registry; it establishes only that they are not reported in the registry record. Interpretation should therefore remain limited to the design, intended measurements, and the absence of posted outcome estimates, rather than conclusions about the direction or magnitude of lipid differences.
9. Statistical Methods Explained
The registry describes a prospective cohort, which follows participants classified by an existing characteristic rather than assigning a treatment at random. In this study, the relevant classification was whether the three hour glucose tolerance test was normal or abnormal. The study summary identifies the abnormal-test group as having gestational diabetes and the normal-test group as not having gestational diabetes. This design can describe differences between the groups, but it does not by itself separate the effect of gestational diabetes from other characteristics that may differ between them.
What does a cohort comparison estimate?
In general, a cohort comparison estimates how an outcome differs across groups as observed. The comparison is not automatically a causal effect. Causal interpretation requires careful consideration of factors related both to group membership and to the outcome. The registry record does not report a prespecified adjustment strategy, the covariates considered, or any adjusted estimates. It also states that the arms are not a like-for-like control comparison and that allocation is not stated.
How should the primary outcome summaries be read?
The primary outcome is postpartum cholesterol in mg/dl. The registry identifies the parameter as a mean and the dispersion measure as an inter-quartile range. In general, the mean is sensitive to unusually high or low observations, while the inter-quartile range describes the spread of the central half of observations. Reporting both can help characterize a distribution, but without the actual summaries readers cannot assess the observed level, variability, or group contrast. The record does not report an endpoint estimate, standard error, confidence interval, or test statistic.
The timing is described as at least 6 weeks postpartum. This specifies a minimum interval after delivery but does not identify the full range of collection times or whether timing was similar across groups. If measurement timing varies, interpretation may depend on whether the timing itself is associated with lipid values. The record does not describe that issue or a method for accounting for it.
What can be inferred from the planned sample-size illustrations?
The registry includes assumptions for planning illustrations based on an observed effect: a two-sided significance level of 0.05, equal allocation, a normal approximation, and effects defined as fractions of the observed effect. Such calculations are planning illustrations, not observed power. They describe participant requirements under specified assumptions, rather than the probability that a completed study has detected a real effect. The registry record does not report the observed effect used, the calculated participant requirements, or the effect fractions associated with the illustrations. It also does not report the trial's own sample-size justification, so these illustrations should not be treated as evidence of the study's original design rationale.
General statistical explanation: sample-size calculations depend on the size of the effect one wants to detect, variability, the chosen significance level, and the desired power. If an assumed effect is smaller, more information is generally needed to distinguish it from random variation. In this record, no numerical planning result is available to assess, and no observed outcome estimates are posted from which to judge precision.
Why can over-dispersion matter?
General statistical explanation: over-dispersion occurs when outcome variability is greater than a model assumes. When that happens, standard errors from an under-dispersed model can be too small, making estimates appear more precise than they are. The primary outcome is a continuous cholesterol measure, and the registry does not report a model or any over-dispersion assessment. No conclusion about whether over-dispersion was relevant can be drawn from the record.
What does the analysis record establish?
The registry lists zero analyses. It does not provide an analysis method for the primary outcome or the secondary measures of triglycerides, HDL and LDL. There is no reported method for handling missing observations, checking model assumptions, adjusting for covariates, or estimating uncertainty. These omissions prevent an independent assessment of the statistical approach and mean the intended measurements cannot be converted into evidence about group differences from this record alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies cholesterol as the primary outcome and lists triglyceride values, HDL and LDL as secondary outcomes. It also lists four outcome measures overall, but records zero analyses. No outcome estimates or hypothesis tests are reported, so the record does not show which outcomes were analyzed or whether any produced statistically distinguishable group results.
When multiple outcomes or comparisons are examined, general statistical practice considers multiplicity: the more opportunities there are to find an apparently notable result, the greater the chance of at least one such result arising by chance. A prespecified testing hierarchy or adjustment can address some multiplicity concerns. The registry record does not report a multiplicity plan, adjustment method, or testing hierarchy. It is therefore not possible to determine how multiple outcomes were handled.
Missing-data procedures are also not reported in the registry record. The record does not state how many participants contributed postpartum cholesterol values, whether all enrolled participants completed follow-up, or how missing measurements were handled. The primary outcome population field is blank. The group-specific counts in the safety record do not establish the number included in any lipid analysis.
Analysis-population definitions, such as whether all enrolled participants or only those with observed postpartum measurements were included, are not reported in the registry record. There is also no reported information about exclusions, protocol deviations, or sensitivity analyses. These gaps limit the ability to assess selection bias and the robustness of any potential outcome comparison.
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 |
|---|---|---|---|
| Gestational Diabetics | 0 | 47 | 0.0% |
| Normal Pregnancies | 0 | 59 | 0.0% |
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 |
|---|---|
| Gestational Diabetics | 0 of 47 |
| Normal Pregnancies | 0 of 59 |
The adverse-event record lists the gestational diabetic group with 47 participants at risk and 0 serious adverse events; it also lists 47 at risk and 0 other adverse events. The normal pregnancies group has 59 participants at risk and 0 serious adverse events, with 59 at risk and 0 other adverse events. These are the counts recorded in the registry.
The record does not report deaths for either group. It also does not list serious adverse-event terms. A count of 0 in the posted results means no events of that category are recorded for the listed group; it should not be read as proof that no event occurred outside the reporting scope or period. The record does not describe the adverse-event collection window, definitions, or monitoring procedures, so those details cannot be used to interpret the zero counts.
These safety counts are not lipid outcome results and do not provide evidence about cholesterol, triglyceride, HDL or LDL differences. The at-risk denominators also should not be assumed to be the denominators for the primary outcome, because the record does not identify the outcome analysis populations.
12. What the Result Does, and Does Not, Mean
The registry record documents a completed prospective cohort study intended to compare lipid measures in women with gestational diabetes and women with normal glucose tolerance. It identifies postpartum cholesterol as the primary outcome and describes additional lipid measurements during pregnancy and from umbilical cord blood. Those details clarify the study's aims and measurement plan.
The record does not report the cholesterol results, secondary outcome values, group contrasts, confidence intervals, or statistical tests. It therefore cannot establish whether the groups differed, how large any difference may have been, or how precisely a difference was estimated. The absence of analyses in the registry is not evidence that the groups were equal; it means that a result for judging equality or difference is not reported in the registry record.
General statistical explanation: a nonsignificant test, if one were reported, would not by itself prove that groups are equivalent. Assessing equivalence requires an appropriate design, a defined margin, and estimates precise enough to exclude differences beyond that margin. No such information is reported in this record.
The observational design also matters. Because the groups were defined by glucose tolerance test results rather than randomized assignment, a difference in lipid measures could reflect other group differences as well as the diagnostic classification. The registry does not report adjusted comparisons or the variables used to address potential confounding. No causal conclusion is supported by the design information alone.
The findings that can be described from this registry entry are therefore procedural and administrative: the study is marked completed, enrollment is listed as 106, and the planned outcome domains are stated. The clinical outcome question remains unanswered by the posted results. The record should not be used to claim either a beneficial or harmful effect, or to make a recommendation about screening or care.
13. Why This Trial Matters Statistically
This study is statistically notable as a cohort comparison in which the groups arise from a diagnostic test rather than random assignment. That structure makes clear why a difference in outcomes and a causal effect are not the same thing. Descriptive contrasts can be informative, but causal interpretation depends on design and analysis choices that are not documented in the registry record.
The study also links measurements taken at different times: lipid panels around glucose testing, cord blood lipid profiles, and maternal cholesterol postpartum. These measurements address related but distinct questions. Their timing and analysis populations matter for interpreting any comparison, yet the registry does not report the complete follow-up or analysis details.
Statistically, the key issue is not only whether an estimate might differ between groups, but also how precisely it is estimated and how the analysis handles multiple outcomes and missing observations. The record lists several lipid outcomes but no analyses, uncertainty intervals, or missing-data approach. Consequently, readers cannot assess the magnitude, precision, or robustness of an outcome contrast from the registry results.
The record also illustrates the distinction between enrollment and analysis denominators. It lists total enrollment of 106, a planned comparison of 46 women in each group in the study summary, and different at-risk counts in the safety record. These counts do not establish who contributed to the postpartum outcome analysis, which is not reported.
These statistical considerations matter because the study's aims concern group comparisons and possible postpartum risk, while the available registry results do not report the estimates needed to evaluate those questions. Clear reporting of outcome values, uncertainty, analysis populations and methods would be necessary to interpret the evidence.
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 important limitation of the registry entry is the absence of reported outcome analyses. No postpartum cholesterol values, secondary lipid results, group contrasts, confidence intervals, or p-values are recorded. The statistical evidence for the study's stated comparisons therefore cannot be evaluated from this record.
The study summary is truncated, and several design details are not reported in the registry record. The record does not describe a sample-size justification, the planned analysis methods, covariate adjustment, missing-data handling, analysis populations, or multiplicity procedures. The primary outcome population field is blank. The record also does not explain how the reported enrollment of 106 relates to the summary's planned comparison of 46 women per group or to the safety at-risk counts.
The comparison is observational, with groups based on glucose tolerance test results. The registry cautions that the arms are not a like-for-like control comparison and does not state an allocation approach. The record does not provide sufficient detail to assess comparability between groups or the role of potential confounding.
The primary outcome is described as postpartum cholesterol collected at least 6 weeks postpartum, but the range and consistency of collection times are not stated. The record does not report follow-up completeness or whether all enrolled participants had postpartum measurements. These omissions limit interpretation of both representativeness and precision.
Finally, the adverse-event record does not state its observation window or provide deaths data. Its counts should be read only as the events recorded for the listed groups, not as a complete description of all possible safety observations.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Lipid Metabolism in Gestational Diabetes — NCT00534105.
- Registry record last updated 2013-09-11; status last verified 2013-07.
- Results first posted 2013-09-11.
- 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
NCT00534105 is a completed prospective cohort study titled Lipid Metabolism in Gestational Diabetes, sponsored by Baystate Medical Center. The registry lists enrollment of 106, with a start date of 2007-09 and primary completion in 2010-11.
The study summary describes comparing women with an abnormal three hour glucose tolerance test and women with a normal result. It describes lipid measurements during pregnancy and cord blood sampling. The primary outcome is postpartum cholesterol in mg/dl, obtained at least 6 weeks postpartum and summarized as a mean with an inter-quartile range. Triglyceride values, HDL and LDL are listed as secondary outcomes.
The registry records zero analyses and does not report outcome estimates or statistical comparisons. It does not report analysis populations, missing-data procedures, multiplicity methods, or a trial-specific sample-size justification. The safety record lists zero serious and zero other adverse events for both groups; deaths are not reported in the registry record.