Effects of Docosahexaenoic Acid (DHA) on Fetal Cardiac Outcomes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effects of Docosahexaenoic Acid (DHA) on Fetal Cardiac Outcomes (NCT01007110), a randomized phase 3 study. The primary outcome is Heart Rate.

2. Clinical Question

The registry record asks whether maternal docosahexaenoic acid (DHA) supplementation is associated with fetal cardiac outcomes during pregnancy. Its stated hypothesis is that supplementation will lower fetal heart rate (HR) and increase fetal heart rate variability (HRV). The primary endpoint is mean fetal HR, measured at 24, 32 and 36 weeks gestational age. HRV is part of the stated hypothesis, but a result for HRV is not reported in the registry record.

This is a question about a repeated physiologic measurement during pregnancy, not a reported test of later clinical outcomes. Secondary outcomes listed in the record include neonatal behavioral assessment scores, maternal red blood cell phospholipids at delivery, cord blood phospholipids DHA, and cardiac conduction time. Their results are not reported in the registry record. The stated biological rationale provides context for the question, but it does not establish what the trial found.

3. Trial Design

The record identifies NCT01007110 as a Phase 3, randomized, double-masked, parallel trial sponsored by the University of Kansas. Its status is completed. The recorded start is 2009-05 and the primary completion is 2011-05. Registry enrollment is 67. These design and enrollment details describe the registered study; they do not supply the outcome estimates or establish how many observations contributed to any particular analysis.

The two arms are Docosahexaenoic Acid (DHA) and Placebo. The placebo is described as soy/corn oil. Randomized allocation means the study design assigned participants to arms by a random process, but the particular sequence-generation and allocation-concealment methods are not reported in the registry record. Double masking indicates that masking was part of the design; which people were masked and how masking was maintained are not reported in the registry record. The record calls the study parallel, meaning the named arms are separate study groups rather than periods in a crossover design.

The primary endpoint is mean fetal HR measured by magnetocardiogram at 24, 32 and 36 weeks gestational age. The record reports the number of subjects contributing to that measure separately by arm and visit: placebo has 19 at 24 weeks, 25 at 32 weeks, and 24 at 36 weeks; DHA has 21 at 24 weeks, 23 at 32 weeks, and 22 at 36 weeks. These visit-specific counts should not be treated as a single analysis sample or added together: repeated visits may involve the same participants, and the record does not explain why the counts vary.

The registry record does not report the detailed protocol, recruitment approach, eligibility criteria, randomization ratio, planned sample-size justification, or statistical analysis plan. It also does not report a primary outcome estimate, uncertainty interval, or test comparing the arms. The completed status therefore indicates the recorded study status, not that a numerical result is available in the 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.

Allocation

Follow-Up at 24 Weeks

Follow-Up at 32 Weeks

Follow-Up at 36 Weeks

Analysis population for the primary outcome, as defined in the registry: Placebo: 19 subjects @ 24 wks GA, 25 subjects @ 32 wks GA, 24 subjects @ 36 wks GA DHA: 21 subjects @ 24 wks GA, 23 subjects @ 32 wks GA, 22 subjects @ 36 wks GA

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 Heart Rate, measured over 24, 32 and 36 weeks gestational age.

The primary endpoint is mean fetal heart rate, expressed in beats per minute. It is calculated from magnetocardiogram recordings obtained at 24, 32 and 36 weeks gestational age. The registry record describes the endpoint as a mean and lists standard deviation as its measure of dispersion. The primary measure is therefore a continuous physiologic outcome, with a group mean intended to describe the typical recorded rate at each visit and a standard deviation describing the spread of individual measurements around that mean.

As general statistical context, a continuous measure can retain distinctions among observed values rather than reducing them to categories. Reporting the measure at several gestational ages can describe its pattern over time, but interpretation depends on how repeated observations were analyzed and whether the same participants contributed across visits. The registry record gives visit-specific participant counts, but does not explain the analysis of repeated measures, the handling of observations that were unavailable, or whether the primary comparison concerned one visit, all visits, or a trajectory.

The record’s rationale describes a hypothesis about lower fetal HR and increased fetal HRV with maternal DHA supplementation. HR is the named primary endpoint; HRV is not reported as a primary result in the registry record. The endpoint provides a measure of fetal cardiac rate, but a difference in that measure alone would not establish effects on other outcomes. The biological or clinical importance of any observed difference cannot be judged from the endpoint definition alone, and no group means, treatment contrast, or uncertainty estimate is reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Mean fetal HR is a continuous outcome, and the registry record identifies the mean as the parameter of interest and standard deviation as the dispersion measure. General statistical context helps explain what those summaries would convey, but the numerical summaries and inferential results are not reported in the registry record.

What does a mean describe?

For a continuous measurement, the mean is an average across observed values. It gives a concise description of the group’s central level, while the standard deviation describes how spread out those values are around the mean. The standard deviation is not the same as the precision of the mean: precision also depends on how many observations contribute and on features of the study design. The registry record reports visit-specific subject counts but does not report the means or standard deviations for either arm.

What would a treatment contrast mean?

In a comparison of randomized arms, a treatment contrast would quantify how the outcome differs between the DHA and placebo groups under a specified analysis. The interpretation depends on the scale and direction used. For example, a contrast could be expressed as the DHA mean relative to the placebo mean, but the registry record does not report a contrast or specify its direction. No effect should be inferred from the hypothesis in the brief summary. A numerical estimate would be needed to describe the observed difference, and an uncertainty measure would be needed to communicate how precisely it was estimated.

How should a confidence interval be understood?

As general statistical explanation, a confidence interval is a range of values generated by a procedure designed to reflect uncertainty in an estimate. It describes the compatibility of the data with a range of effects under the assumptions of that procedure; it is not a guarantee that the true effect lies within the particular interval. A narrow interval generally indicates greater precision than a wide one, all else being equal. The registry record does not report a confidence interval for fetal HR, so the precision of the treatment comparison cannot be evaluated.

What role does a p-value play?

As general explanation, a p-value measures how unusual the observed data, or data more extreme, would be under a specified null model and its assumptions. It is not the probability that the null hypothesis is true, and it does not indicate the clinical importance of an effect. Interpretation should consider the estimate and its uncertainty, not a threshold alone. No p-value or test result for the primary endpoint is reported in the registry record.

Why does the schedule matter?

The endpoint is assessed at 24, 32 and 36 weeks gestational age. Multiple measurements can be analyzed separately at each visit or together in a model that accounts for their relationship within participants. As general statistical context, observations from the same participant are often correlated, so treating them as independent can give an inaccurate account of uncertainty. A repeated-measures approach can represent that dependence, but the appropriate model depends on the analysis question and data structure. The registry record does not state which method was used, whether the primary question focused on a particular visit, or whether an overall time pattern was the target.

The number of subjects listed for the endpoint differs across the visits and arms. This information is relevant to interpreting the amount of outcome data available at each time point, but does not identify the reason for the differences. The registry record does not describe missing-data methods, whether measurements were excluded, or how the analysis population was defined. General statistical practice distinguishes the number randomized from the number with an observed measurement at a given visit; those quantities are not interchangeable.

Why can variability affect inference?

As general explanation, greater variation in measurements can make a group mean less precisely estimated when other design features are unchanged. If data are more variable than a model assumes, standard errors and tests based on that model may be unreliable. Over-dispersion is one name for variation beyond what a particular model expects; it matters when the outcome’s distribution and the model’s assumptions do not align. The registry record specifies mean and standard deviation for the endpoint, but does not provide the data distribution or enough analysis detail to assess model fit or over-dispersion. The endpoint is continuous, so this concern is not evidence that over-dispersion occurred in this trial.

The record describes a sample-size planning illustration based on the observed effect. It gives the assumptions of a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect set as a stated fraction of the observed effect. These are planning assumptions, not evidence about the trial’s design or its realized statistical power. The planning values and observed effect are not reported in the registry record. The record explicitly distinguishes participant-per-arm planning illustrations from total-event calculations for time-to-event settings; this trial’s primary endpoint is a continuous measure, not a time-to-event outcome. No trial-specific sample-size justification is reported in the registry record.

Randomization, masking, and a parallel-arm design describe important features of the study structure, but they do not alone establish the validity of a particular analysis. A complete interpretation would also require the prespecified endpoint definition, the comparison and model, handling of repeated measurements and missing values, and numerical effect estimates with uncertainty. Those details are not reported in the registry record. The posted information therefore permits explanation of the endpoint and general statistical concepts, but not a reconstruction or verification of the primary analysis.

10. Multiplicity, Missing Data and Analysis Populations

The primary endpoint is scheduled at 24, 32 and 36 weeks gestational age, and several secondary outcomes are listed. Considering several time points or outcomes can create multiplicity: the more comparisons examined, the greater the chance that at least one result appears notable by chance when each is assessed separately. General statistical approaches can address this by prespecifying a primary comparison, adjusting inference across comparisons, or treating secondary analyses as exploratory. The registry record does not report a multiplicity strategy, a hierarchy among time points, or which comparison was designated as the primary statistical test.

The record lists the primary measure’s subject counts separately for each arm and visit. The counts vary by visit, but the reasons are not reported in the registry record. It does not state whether values were missing, whether participants could not be measured at a particular visit, or whether any observations were excluded. A reader therefore cannot determine whether missingness may have affected the comparison or how it was handled.

The registry record does not describe an intention-to-treat population, a per-protocol population, or another analysis population. It does not report whether all randomized participants were included in the analysis according to their assigned arm. Enrollment is recorded as 67, but that figure does not replace the visit-specific counts or identify the analysis population. No imputation method or sensitivity analysis for missing outcome values is reported. These omissions limit assessment of how robust a primary estimate would be to missing observations or analytic choices. No analysis records are listed, and numerical results for the secondary outcomes are not reported in the registry record.

11. Safety Results

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

Other (non-serious) adverse events

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

The registry record lists serious adverse events and other adverse events separately for the placebo and DHA arms. For serious adverse events, it records zero affected participants among 32 at risk in the placebo arm and zero among 35 at risk in the DHA arm. For other adverse events, it records zero affected participants among 32 at risk in the placebo arm and zero among 35 at risk in the DHA arm. These counts describe the adverse-event entries in the record; they are not an estimate of comparative risk with a reported uncertainty interval.

As general statistical context, a zero count means that no events were recorded in the specified category and group in this registry entry. It does not prove that the underlying event rate is zero or that an event could not occur. The precision of an estimate based on zero events depends on the amount and completeness of safety follow-up and on the event definitions. Those details are not reported in the registry record. The record also does not provide the reasons for the listed numbers at risk, the timing of safety collection, or a statistical comparison of adverse events between arms.

Deaths are not reported in the registry record. The absence of a reported death count should not be interpreted as a reported zero. These safety entries should be read narrowly as recorded counts for the listed categories and groups, not as a complete account of all possible harms or a basis for a treatment recommendation.

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

The registry record establishes that a randomized, double-masked, parallel trial assessed mean fetal HR in the DHA and placebo arms at 24, 32 and 36 weeks gestational age. It identifies magnetocardiogram as the measurement method and gives the number of subjects contributing at each visit. It also records the trial as completed and lists its enrollment and intervention descriptions. These details define the study question and the available structure of the registered endpoint information.

The record does not provide the group means, standard deviations, treatment contrast, confidence interval, or p-value for fetal HR. It therefore does not show whether the groups differed, in what direction any observed difference went, how large it was, or how precisely it was estimated. The hypothesis that maternal DHA supplementation would lower fetal HR and increase fetal HRV is not evidence that either outcome changed. The record does not report a result for HRV.

Even if a numerical difference were available, interpreting it would require attention to the endpoint definition, gestational-age visits, analysis of repeated measurements, missing data, and the analysis population. The registry record does not report those analytical details. Nor does it report results for the listed secondary outcomes. The adverse-event counts are zero for the listed categories and groups, but this is not equivalent to proof that events cannot occur or a comprehensive assessment of safety.

As general statistical context, a study’s result and its precision answer different questions. An estimate describes the observed contrast, while an uncertainty interval describes how much uncertainty remains under the analysis assumptions. A p-value alone would not establish the size or importance of an effect. None of these primary comparison statistics is reported in the registry record. The appropriate interpretation is therefore limited: the registered information describes a trial designed to investigate fetal cardiac measures, but does not establish what the trial found about its primary endpoint or whether an effect was precise or important.

13. Why This Trial Matters Statistically

This trial illustrates why a clear endpoint definition is necessary but not sufficient for statistical interpretation. The registry record specifies mean fetal HR, its measurement method, units, and gestational-age schedule. Those details let readers understand what was intended to be measured. To evaluate a treatment comparison, however, readers also need the outcome summaries, effect estimate, uncertainty, and analysis approach. Those results and methods are not reported in the registry record.

The schedule raises a general design and analysis issue: a participant may contribute measurements at more than one gestational age. Repeated measurements can provide information about change over time, but they are related observations rather than automatically independent data points. The analysis must match the question—such as comparing arms at a visit or describing a pattern across visits—and account appropriately for the data structure. The registry record supplies visit-specific counts but does not state which comparison or model was used.

The record also demonstrates the importance of distinguishing enrollment from outcome availability. It reports enrollment of 67 and separate subject counts for the endpoint at each visit and arm. These values answer different descriptive questions. Because the reason for the changing counts is not reported, readers cannot infer the amount or pattern of missing information or its handling.

Finally, a stated hypothesis and a completed study status do not substitute for a posted result. A registry entry can describe a clinically motivated question and key design features while leaving the primary statistical evidence unavailable. This distinction matters for transparent interpretation: the design can be discussed, but the effect and its precision cannot be judged without the outcome statistics and analysis details.

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 interpreting this trial from its registry record is that primary outcome results are not reported. There are no numerical group means, standard deviations, estimated contrast, confidence interval, or p-value for fetal HR. As a result, the direction and magnitude of the observed comparison, and its precision, cannot be assessed. The stated hypothesis should not be mistaken for an outcome finding.

The record does not explain the primary statistical analysis. In particular, it does not say how measurements from 24, 32 and 36 weeks gestational age were handled, whether the principal comparison was tied to one visit or all visits, or how repeated observations were modeled. It lists different numbers of subjects by arm and visit without explaining why. Missing-data methods and the analysis population are not reported in the registry record.

Although the design is identified as randomized, double-masked, and parallel, further implementation details are not reported. The sequence-generation method, allocation concealment, masking procedures, and randomization ratio are not specified. Eligibility criteria and participant characteristics are also not reported in the registry record, limiting assessment of who the findings would describe even if results were available.

The record lists secondary outcomes but does not report their results or describe a plan for controlling multiplicity. It does not provide a trial-specific sample-size justification, and the planning illustration is not a substitute for the original design rationale or observed results. The safety record contains zero reported events in the listed categories, but does not provide enough detail about safety follow-up and event ascertainment to establish that all potential safety outcomes were captured. These limitations concern what can be learned from the registry record; they do not show that the trial lacked procedures or analyses that are not recorded there.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Effects of Docosahexaenoic Acid (DHA) on Fetal Cardiac Outcomes — NCT01007110.
• Registry record last updated 2014-06-09; status last verified 2014-06.
• Results first posted 2014-05-14.
• 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

NCT01007110 is recorded as a completed Phase 3, randomized, double-masked, parallel trial sponsored by the University of Kansas. The condition is pregnancy; the recorded start is 2009-05, primary completion is 2011-05, and enrollment is 67. The study compares a DHA arm with a soy/corn oil placebo arm.

The primary endpoint is mean fetal HR in beats per minute, calculated from magnetocardiogram recordings at 24, 32 and 36 weeks gestational age. The record lists visit-specific subject counts for each arm but does not explain their variation. It identifies secondary outcomes related to neonatal behavioral assessment, maternal and cord blood phospholipids, and cardiac conduction time.

Numerical primary and secondary outcome results, the primary statistical comparison, missing-data methods, and the analysis population are not reported in the registry record. The listed adverse-event counts are zero for serious and other adverse events in both arms; deaths are not reported. The entry describes the study question and design, but does not provide sufficient outcome statistics to determine the primary treatment effect or its precision.