<scp>OC</scp>26.05: Aortic isthmus and umbilical artery Doppler for the prediction of intra uterine fetal demise after laser photocoagulation in twin–twin transfusion syndrome
Bibliographic record
Abstract
To evaluate changes in systolic flow through the aortic isthmus reflecting the relative performances of the left (LV) and right (RV) ventricles in monochorionic pregnancies complicated by twin–twin transfusion syndrome (TTTS). To compare the values of the isthmic systolic index (ISI, nadir of end-systolic velocity / peak systolic velocity) before and after treatment with laser photocoagulation, and between donor and recipient twin. To assess the prognostic value of the ISI to predict the intra-uterine fetal demise (IUFD) of each twin. Fetal echocardiography and outcome data of 90 cases of TTTS treated by laser photocoagulation between 2007 and 2013 were retrospectively reviewed. The aortic isthmus flow was measured in the sagittal plane in both donor and recipient twin, before and after laser treatment of TTTS. The Doppler measures of the aortic isthmus were available in 29 twin pregnancies pre laser and 25 post laser. Statistics used the Fisher exact test, the Mann-Whitney U-test or the Wilcoxon test. Before laser, the median ISI was 0.17 [interquartile range 0.13–0.25] in the donor and 0.19 [0.15–0.23] in the recipient. After laser, the median ISI was 0.19 [0.14–0.26] in the donor and 0.19 [0.15–0.24] in the recipient (all p > 0.05). Pre and post laser ISI values were similar to those of healthy fetuses at the same gestational age. Amongst the 90 cases, IUFD occurred in 11 donors and 14 recipients. Values of the ISI did not differ between cases of IUFD and controls, both in the donor and the recipient, before and after laser photocoagulation. The sole predictor of donor IUFD was a preoperative absent or reversed end-diastolic (ARED) flow in the donor (p = 0.03), and the sole predictor of recipient IUFD was a post-operative ARED flow in the recipient (p = 0.02). We found no significant impairment in the LV and RV relative performances in TTTS treated by laser photocoagulation. ARED flow in the umbilical artery was associated with IUFD after laser treatment.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.012 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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 teacher head, 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".