Changes in velocimetric indices of uterine and umbilical arteries before and after combined spinal epidural analgesia in laboring women: a prospective cohort study
Bibliographic record
Abstract
BACKGROUND: Although combined spinal epidural (CSE) analgesia is an effective technique for labor analgesia, concerns regarding fetal bradycardia still remain. Increased vascular resistance of the uterine (UtA) and/or umbilical arteries (UmA) after CSE could explain the reported occurrence of fetal bradycardia. The aim of this study was to assess the changes in the resistance of UmA and UtA before and after initiation of CSE labor analgesia using ultrasound Doppler pulsatility index (PI). METHODS: This was a prospective, observational study in singleton, full-term laboring participants. Doppler ultrasound PI of the UtA and UmA were obtained before and after CSE at 10 and 30 min. The primary outcome was PI at 10 min. The differences in indices were analyzed using paired t-tests orWilcoxon signed-rank tests, and mixed models were used in the exploratory analyses to assess changes over time. RESULTS: Data were analyzed for 30 participants. Compared to baseline, there was a significant increase in mean UtA PI (Δ 27 %, P = 0.029) at 10 min, however no significant difference was observed in the UmA PI. UtA PI showed a significant increase over time (coefficient 0.05, P = 0.002), while no changes were observed in UmA PI or fetal heart rate. CONCLUSION: Our study suggests that CSE for labor analgesia may be associated with a discrete increase in maternal UtA resistance, however, these changes are not reflected in UmA resistance in the fetus, providing reassurance that CSE with low-dose local anesthetic is a safe analgesic technique in labor.
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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 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".