OpiCalc Logo

OpiCalc

--- Clinical Tools

Logo
OpiCalc
APGAR ScoreAssisted Delivery (FIGO)BPP (Manning Score)Bishop ScoreCARPREG II Cardiac RiskCervical Cancer StagingContraceptive Pearl IndexDoppler Matrix (UA/MCA)EFW (Hadlock)Endometrial StagingEndometrial ThicknessFGR Criteria (Consensus)FSFI (Sexual Function)Ferriman-Gallwey ScoreFetal Anemia (MCA PSV)GDM Diagnostic CriteriaGPA History IndicatorGail Model Breast RiskGestational Dating (LMP)HIV PMTCT ProtocolIOTA Simple RulesIVF Due Date & AMHIron Deficit (Ganzoni)Labour Progress (WHO)Maternal Sepsis (qSOFA)O-RADS ClassificationOvarian Cancer StagingPAS Hemorrhage RiskPPH Protocol (FIGO)Preeclampsia (ACOG)Rho(D) Dose (K-B)Rotterdam PCOS CriteriaSyphilis ManagementTORCH FrameworkVBAC Success ProbabilityVulvar Cancer StagingWeight Gain (IOM)mWHO Cardiac Risk

Labour Progress (WHO)

WHO Labour Care Guide

FIGO Standard Partograph Monitoring

Success/Alert Thresholds

Active First Stage≥ 5cm Dilation
Normal Rate≥ 1cm / 2 hours
Second Stage (Para 0)Max 3 Hours
Second Stage (Para 1+)Max 2 Hours
Uterine Dynamics

Target: 3-4 contractions per 10 minutes, each lasting 40-50 seconds in the active phase.

Tachysystole Alert

> 5 contractions per 10 mins (Averaged over 30 mins)

The World Health Organization (WHO) has replaced the traditional 4-hour action line with a 1cm per 2-hour action limit to reduce unnecessary interventions.

EVIDENCE SYNTHESIS

Clinical Reference Hub

Curated insights • How it Works • Practical Pearls • Evidence Base

CLINICAL INSIGHT

When to Use

Primary Clinical Uses

  • Continuous monitoring of intrapartum maternal and fetal well-being.
  • Identifying prolonged or obstructed active labor to trigger interventions (amniotomy, oxytocin, cesarean).
  • Completely replacing the legacy 1950s Friedman Curve and the outdated WHO Partograph.

The Paradigm Shift

The rigid "1 cm per hour" rule is dead. Modern evidence shows that physiological labor is entirely non-linear. The WHO Labour Care Guide (LCG) dictates that active labor does not begin until 5 cm of dilation, and allows for significantly slower early progress without intervening.

CLINICAL INSIGHT

How it Works

Defining Active Phase

Latent phase continues until 5 cm of cervical dilation. The active phase is strictly defined as 5 cm to 10 cm. Interventions to accelerate labor should NOT routinely be performed before 5 cm.

Dynamic Alert Thresholds

5 cm to 6 cm
6 cm to 7 cm
7 cm to 8 cm
8 cm to 10 cm
CLINICAL INSIGHT

Practical Pearls

Key Nuances

  • Do not routinely perform amniotomy (breaking the water) or start Oxytocin just because the latent phase (< 5cm) is prolonged, provided maternal/fetal signs are stable.
  • ACOG guidelines (US) differ slightly by defining the onset of the active phase at 6 cm, structurally allowing even more conservative management in the 4-5 cm window compared to the global WHO 5 cm rule.
  • Epidural analgesia routinely adds 1-2 hours to the active phase; thresholds must be mentally adjusted.
CLINICAL INSIGHT

Next Steps

Triggering Interventions

  • Progress crosses the established maximum time limit for the specific centimeter increment.
  • Perform thorough assessment of the 3 P's: Power (contractions), Passenger (fetal position/size), Pelvis.
  • If contractions are inadequate: Consider Artificial Rupture of Membranes (AROM) and Oxytocin augmentation.
  • If adequate contractions (>200 Montevideo units) persist for 4 hours with no cervical change in the active phase: Arrest of active labor. Proceed with Cesarean delivery.
CLINICAL INSIGHT

Evidence Base

WHO Guidelines

WHO recommendations: intrapartum care for a positive childbirth experience.

World Health Organization.Geneva: WHO.2018

Contemporary patterns of spontaneous labor with normal neonatal outcomes.

Zhang J, Landy HJ, Branch DW, et al.Obstet Gynecol.2010
CLINICAL INSIGHT

Background

Emanuel Friedman

In 1955, Dr. Emanuel Friedman studied 500 women and created the "Friedman Curve." For 60 years, it was undisputed dogma. However, modern women are older, have higher BMIs, larger babies, and widely use epidurals, rendering the 1950s data highly dangerously inaccurate and triggering an epidemic of premature cesarean deliveries.