The Valsalva maneuver duration during labor expulsive stage: repercussions on the maternal and neonatal birth condition
Bibliographic record
Abstract
OBJECTIVES: This cross-sectional study was designed to examine the effects of the Valsalva Maneuver (VM) and its duration on the acid- base equilibrium of the neonate and its maternal repercussions during the expulsive stage of labor, after standard breathing and pushing instructions were given. METHODS: A convenience sample of women with low risk pregnancy (n=33; mean age 22.5±3.7 y and gestational age 38.1±1.12 wks) and their newborns were studied during the expulsive stage of vaginal labor. Coaching consisted of standard recommendations for breathing including prolonged VMs coordinated with pushing. Maternal outcomes included the need for uterus fundal pressure maneuver and episiotomy, perineal trauma and posture. Neonatal outcomes included blood gases sampled from the umbilical cord, and Apgar scores. Data were analyzed with the Fisher's exact test, chi-square test, and Pearson correlation coefficient. RESULTS: None of the maternal outcomes were associated with VM duration. With respect to neonatal outcomes, increased VM duration was associated with reduced venous umbilical pH (r=-0.40; p=0.020), venous base excess (r=-0.42; p=0.014) and with arterial base excess (r=-0.36; p=0.043). Expulsive stage time was negatively associated with umbilical venous and arterial pH. CONCLUSIONS: VM duration during fetal expulsion in labor negatively affects fetal acid-base equilibrium and potentially the wellbeing of the neonate. Our results support the need to consider respiratory strategies during labor, to minimize potential risk to the mother and neonate.
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 | 0.000 | 0.000 |
| 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".