Severe left heart obstruction with retrograde arch flow influences fetal cerebral and placental blood flow
Bibliographic record
Abstract
OBJECTIVE: Decreased middle cerebral artery (MCA) pulsatility index (PI) is a marker of fetal brain-sparing in placental insufficiency and it is also found in fetuses with severe congenital heart disease. This study sought to explore the impact of anatomical subtypes in fetal heart disease on MCA-PI and head growth. METHODS: We retrospectively reviewed fetal echocardiograms of pregnancies complicated by fetal hypoplastic left heart syndrome (HLHS; n = 42) with and without anatomic coarctation (n = 28 and n = 10, respectively), isolated severe aortic coarctation (n = 21), D-transposition of the great arteries (TGA; n = 11) and pulmonary outflow tract obstruction without forward flow across the pulmonary valve (POTO; n = 15), comparing observations with gestational age-matched controls (n = 89). No fetus had major extracardiac pathology or aneuploidy. MCA and umbilical artery (UA) PI, the cerebral placental ratio (CPR = MCA-PI/ UA-PI) and neonatal head circumference were obtained and expressed as Z-scores. RESULTS: Lower MCA-PI, higher UA-PI and lower CPR were observed in fetal HLHS and isolated coarctation with reversed arch flow (n = 6) (P < 0.001) but not TGA, POTO or isolated coarctation with antegrade arch flow (n = 15) compared with controls. No difference was found between HLHS with anatomical coarctation and those without; however, MCA-PI correlated positively with neonatal head circumference in HLHS with reversed distal arch flow (r = 0.33, P < 0.05). CONCLUSIONS: Severe left heart obstruction with reversed aortic arch flow is associated with altered fetal cerebral blood flow, and in these conditions, MCA-PI positively correlates with head growth. Anatomical arch obstruction itself may not be a contributing factor to altered MCA flow in fetal HLHS.
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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 | 0.004 |
| 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".