CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-15). The draft was written by AI, the existence of all 2 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.7.
Verdict No. 2623 · Search date 2026-08-15 · Methodology v0.7

Lying down in second-stage labor,
does it really help with Increased spontaneous vaginal birth versus an upright policy?

30-Second Summary
B
Evidence Grade B · 76 · Safety caution
Lying down during second-stage labor increased spontaneous vaginal birth in nulliparous women with low-dose epidural analgesia.
Position should be adjusted according to maternal blood pressure, comfort, motor ability, fetal heart rate, and labor progress. Maternal or fetal warning signs require immediate clinician-directed repositioning.
What the
research shows
The grade is B. BUMPES randomized 3,236 women and included 3,093 in the primary analysis. Spontaneous vaginal birth occurred in 632/1,537 (41.1%) lying down versus 548/1,556 (35.2%) upright. The adjusted risk ratio for upright versus lying was 0.86 (95% CI 0.78 to 0.94), and the NNT for lying was 17 (11 to 40). Independent confirmation is absent, giving B with 76 points.
What the
ads claim
Lying down was a policy of keeping the pelvis horizontal and included lateral positions; it was not rigid supine immobilization. Maternal preference and clinical signals can require position changes.
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Useful facts when choosing a product

  • The lying policy kept the pelvis as horizontal as possible; upright included sitting, kneeling, or standing.
  • The BMJ paper and HTA monograph are two reports of one BUMPES trial.
  • ISRCTN35706297 listed spontaneous vaginal birth as the primary outcome.
Gap Measurement · Verdict 2623 · B 76
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

BUMPES used secure web randomization across 41 UK labor wards, randomizing 3,236 women and analyzing 3,093 (95.6%) as allocated. Spontaneous vaginal birth occurred in 632/1,537 lying versus 548/1,556 upright, adjusted RR 0.86 (0.78 to 0.94) for upright versus lying. ISRCTN35706297 prospectively listed spontaneous vaginal birth as primary, matching the paper. NIHR HTA programme project 08/22/02 funded the trial. The BMJ article and HTA monograph report the same randomization and were counted once.

02

Why this is classified as B (76)

A large publicly funded randomized trial showed a meaningful hard-event difference, but post-randomization exclusions and no independent replication give B with 76 points.

Counterpoint. This applies to second-stage positioning in nulliparous women with low-dose epidural, not multiparous labor, no epidural, breech, or multiple pregnancy.

Rejudgment record. Cross-check applied — The BUMPES BMJ paper, HTA monograph, and ISRCTN35706297 were checked for duplicate reporting, allocation, analyzed counts, primary outcome, and funding

Scoring profile behind this grade
EndpointHHard endpoint - actual events such as death
ReplicationR1Single confirmatory trial
IndependenceI2Decisive evidence is publicly or non-profit funded
Effect sizeE+Meets the clinically important threshold

The scoring table and the verdict agree (B).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Increased spontaneous vaginal birthBRates were 41.1% versus 35.2%, an absolute difference of 5.9 points.
Improved all maternal and neonatal outcomesDMost secondary maternal and neonatal outcomes did not differ clearly.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
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Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Epidural and Position Trial Collaborative Group. 2017 BUMPESPragmatic randomized trial across 41 labor wards1,537NIHR Health Technology Assessment programme, project 08/22/02Primary spontaneous vaginal birth outcomeLying 632/1,537 (41.1%) versus upright 548/1,556 (35.2%); adjusted RR upright versus lying 0.86 (0.78 to 0.94)Only large publicly funded confirmatory trial
Study 2Detailed HTA report of the same BUMPES trial3,093NIHR Health Technology Assessment programmeSame primary spontaneous vaginal birth outcomeSame result as the main paper and not a separate trialSame-trial report used for methods verification
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Receipt — 2 References

All 2 cited sources were verified for existence at the original page (as of 2026-08-15).

Epidural and Position Trial Collaborative Group. Upright versus lying down position in second stage of labour in nulliparous women with low dose epidural: BUMPES randomised controlled trial. BMJ. 2017;359:j4471. PMID: 29046273. PMCID: PMC5646262. DOI: 10.1136/bmj.j4471.
checked
Bick D, Briley A, Brocklehurst P, …, Wilson M; on behalf of the Epidural and Position Trial Collaborative Group. A multicentre, randomised controlled trial of position during the late stages of labour in nulliparous women with an epidural: clinical effectiveness and an economic evaluation (BUMPES). Health Technol Assess. 2017;21(65):1-176. PMID: 29110753. DOI: 10.3310/hta21650.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-15 · Corrections: none

Cite this verdict

Lying down in second-stage labor x increased spontaneous vaginal birth Evidence Grade B card
[Chamgap] Lying down in second-stage labor x increased spontaneous vaginal birth — Evidence Grade B·76. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/womens/lying-down-second-stage-low-dose-epidural-spontaneous-vaginal-birth/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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