A Comprehensive Review of the Research Literature on External Cephalic Version (ECV)
Bibliographic record
Abstract
External cephalic version (ECV) is an approach to turning a fetus from the breech presentation by external maneuvering of the fetus through the maternal abdominal wall into a cephalic presentation. We conducted a systematic search of the current literature on ECV to provide a comprehensive overview of the procedure and associated success rates, risks, and alternatives to ECV. Tocolytics can improve ECV success, but none of the tocolytics shown to be effective for ECV are currently available in Canada. The factors that can best predict ECV success are low uterine tone (associated with parity or tocolytics), easy palpation of the fetal head, and an unengaged breech. The most common side effect of ECV is transient fetal bradycardia with an incidence of one to six percent of all ECV procedures. The risk of requiring an emergency caesarean section because of ECV appears to be around 0.5% or one in 200 ECV procedures performed. Our review suggested no significant risk of fetal/neonatal mortality or serious morbidity associated with ECV. Few alternative approaches to turning a fetus in the breech presentation have been adequately studied. ECV should be considered for all women with a fetus in the breech presentation at term in the absence of any contraindications to the procedure.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.011 | 0.034 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.003 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.008 |
| 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".