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Contraction Timer Deep DiveDevelopers & Healthcare Professionals

5-1-1 Rule Algorithm & Labor Stage Detection

Sophisticated labor monitoring with the 5-1-1 rule, automatic stage classification from Braxton Hicks to Transition, Apple Watch sync, Live Activities, and hospital alert triggering.

4Labor Stages
4Intensity Levels
5-1-1Rule Algorithm
32Languages

Labor Stage Classification

Automatic detection from Braxton Hicks through Transition

StageIntervalDurationIntensityAction
Braxton HicksIrregularVariesMildRest, hydrate
Early Labor10-20 min30-45 secMild-ModerateStay home, time contractions
Active Labor3-5 min45-75 secModerate-StrongGo to hospital (5-1-1 met)
Transition2-3 min60-90 secVery StrongGo to hospital immediately

The 5-1-1 Rule

Clinical guideline for when to go to the hospital

5

5 Minutes Apart

Contractions occur consistently every 5 minutes, measured from the start of one to the start of the next.

1

1 Minute Duration

Each contraction lasts at least 60 seconds. The algorithm checks all recent contractions meet this threshold.

1

1 Hour Consistency

The 5-minute/1-minute pattern has persisted for at least 60 minutes. This prevents false alerts from brief patterns.

Intensity Classification

4-level system with color-coded pain scale

LevelDescriptionPain ScaleColor
MildNoticeable but comfortable, can talk through it1-3Green
ModerateUncomfortable, need to focus, breathing helps4-6Yellow
StrongPainful, difficult to talk, need to concentrate7-8Orange
Very StrongIntense pain, cannot talk, vocalizing9-10Red

Platform Integration

Apple Watch, Live Activities, and data export

Apple Watch Sync

Start and end contractions from your wrist via WatchConnectivity. Real-time bidirectional sync between iPhone and Apple Watch.

Live Activity

Dynamic Island shows active contraction timer with duration and intensity. Lock Screen widget displays ongoing contraction status.

CSV Export

Export complete contraction history with start time, duration, interval, and intensity for your healthcare provider.

Hospital Alert Triggers

Automatic notifications when criteria are met

5-1-1 Rule Met

Automatic alert when contractions are 5 min apart, 1 min duration, for 1 hour.

Transition Detected

Contractions 2-3 min apart with 60+ sec duration and very strong intensity always trigger an alert.

Water Broke

User-reported water breaking triggers immediate hospital alert regardless of contraction pattern.

Alert Actions

Call hospital, call partner, start navigation to hospital, or dismiss with confirmation.

Frequently Asked Questions

Common questions about the contraction timer

Time Contractions with Confidence

Download ProbaBaby for the smartest contraction timer with 5-1-1 rule detection, Apple Watch sync, and automatic hospital alerts.

Free to downloadNo subscription10 free credits