Fetal cardiac and neonatal cerebral hemodynamics and oxygen metabolism in transposition of the great arteries
Bibliographic record
Abstract
ABSTRACT Objectives Hemodynamic abnormalities and brain development disorders have been reported previously in fetuses and infants with transposition of the great arteries and intact ventricular septum (TGA‐IVS). A ventricular septal defect (VSD) is thought to be an additional risk factor for adverse neurodevelopment, but literature describing this population is sparse. The objectives of this study were to assess fetal cardiac hemodynamics throughout pregnancy, to monitor cerebral hemodynamics and oxygen metabolism in neonates, and to compare these data between patients with TGA‐IVS, those with TGA‐VSD and age‐matched controls. Methods Cardiac hemodynamics were assessed in TGA‐IVS and TGA‐VSD fetuses and compared with healthy controls matched for gestational age (GA) during three periods: ≤ 22 + 5 weeks (GA1), 27 + 0 to 32 + 5 weeks (GA2) and ≥ 34 + 5 weeks (GA3). Left (LVO), right (RVO) and combined (CVO) ventricular outputs, ductus arteriosus flow (DAF, sum of ante‐ and retrograde flow in systole and diastole), diastolic DAF, transpulmonary flow (TPF) and foramen ovale diameter were measured. Aortic (AoF) and main pulmonary artery (MPAF) flows were derived as a percentage of CVO. Fetal middle cerebral artery and umbilical artery (UA) pulsatility indices (PI) were measured and the cerebroplacental ratio (CPR) was derived. Bedside optical brain monitoring was used to measure cerebral hemoglobin oxygen saturation (SO2) and an index of microvascular cerebral blood flow (CBFi), along with peripheral arterial oxygen saturation (SpO2), in TGA‐IVS and TGA‐VSD neonates. Using hemoglobin (Hb) concentration measurements, these parameters were used to derive cerebral oxygen delivery and extraction fraction (OEF), as well as an index of cerebral oxygen metabolism (CMRO2i). These data were acquired in the early preoperative period (within 3 days after birth and following balloon atrial septostomy) and compared with those of age‐matched healthy controls, and repeat measurements were collected before discharge when vital signs were stable. Results LVO was increased in both TGA groups compared with controls throughout pregnancy. Compared with controls, TPF was increased and diastolic DAF was decreased in TGA‐IVS fetuses throughout pregnancy, but only during GA1 and GA2 in TGA‐VSD fetuses. Compared with controls, DAF was decreased in TGA‐IVS fetuses throughout pregnancy and in TGA‐VSD fetuses at GA2 and GA3. At GA2, AoF was higher in TGA‐IVS and TGA‐VSD fetuses than in controls, while MPAF was lower. At GA3, RVO and CVO were higher in the TGA‐IVS group than in the TGA‐VSD group. In addition, UA‐PI was lower at GA2 and CPR higher at GA3 in TGA‐VSD fetuses compared with TGA‐IVS fetuses. Within 3 days after birth, SpO2 and SO2 were lower in both TGA groups than in controls, while Hb, cerebral OEF and CMRO2i were higher. Preoperative SpO2 was also lower in TGA‐VSD neonates than in those with TGA‐IVS. From preoperative to predischarge periods, SpO2 and OEF increased in both TGA groups, but CBFi and CMRO2i increased only in the TGA‐VSD group. During the predischarge period, SO2 was higher in TGA‐IVS than in TGA‐VSD neonates, while CBFi was lower. Conclusions Fetal cardiac and neonatal cerebral hemodynamic/metabolic differences were observed in both TGA groups compared with controls. Compared to those with TGA‐IVS, fetuses with TGA‐VSD had lower RVO and CVO in late gestation. A higher level of preoperative hypoxemia was observed in the TGA‐VSD group. Postsurgical cerebral adaptive mechanisms probably differ between TGA groups. Patients with TGA‐VSD have a specific physiology that warrants further study to improve neonatal care and neurodevelopmental outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
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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 | 0.000 | 0.001 |
| 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) | 0.001 | 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".