Relevance of measuring diastolic time intervals in the ductus venosus during the early stages of twin–twin transfusion syndrome
Bibliographic record
Abstract
OBJECTIVE: To determine if the discrete myocardial diastolic dysfunction documented previously in the recipient twin during the early stages of twin-twin transfusion syndrome (TTTS) has any repercussion on flow velocities through the ductus venosus (DV) and to investigate if this could allow early differentiation between TTTS and selective intrauterine growth restriction (IUGR). METHODS: Two groups of monochorionic twin pregnancies with growth discordance between twins were reviewed retrospectively. Group I was composed of fetuses in Stages I and II of TTTS; laser or amnioreduction was not performed in any instance. Group II twin pairs each included one fetus with IUGR due to placental circulatory insufficiency. Intertwin differences (smaller minus larger fetus) were analyzed for myocardial performance index of the right ventricle (MPI-RV) and for time variables in the DV. RESULTS: There were 38 pairs of monochorionic twins (24 TTTS and 14 IUGR) in this study. In the TTTS group, the donors had a significantly lower MPI-RV (0.419 +/- 0.18 vs. 0.596 +/- 0.17, F(1,19df) = 24.017, P < 0.001), a significantly longer total ventricular filling time (150.9 +/- 25.6 ms vs. 124.0 +/- 22.6 ms; F(1,21df) = 19.631, P < 0.001) and a significantly longer early filling time (118.9 +/- 22.9 ms vs. 92.6 +/- 18.9 ms, F(1,21df) = 28.419, P < 0.001) than had the recipient. None of these three differences was present in the IUGR group. Probability studies revealed that cut-off values of 12.75 for intertwin differences in total filling time and 8.5 for intertwin differences in early filling time had sensitivities of 71% and 92%, respectively. The false-positive rates were 23% and 15%, respectively, for the early diagnosis of TTTS. CONCLUSION: In monochorionic twin pregnancies, shortening of the ventricular filling time in the recipient twin indicates diastolic myocardial dysfunction occurring early in the pathophysiology of TTTS. This early interwin difference in myocardial function is not found in pregnancies with IUGR in one twin due to placental circulatory insufficiency, allowing early differentiation between TTTS and selective IUGR.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".