Labor contraction glossary

Labor contraction glossary

This labor contraction glossary explains common words you may hear while timing contractions, calling triage, or preparing for birth. Definitions are general, and your obstetrician or midwife’s instructions should take priority.

What contraction timing terms mean

Contraction language describes what you feel and what a timer records. Timing can reveal a pattern, but it cannot confirm labor or show cervical change.

Contraction

A tightening of the uterus that may cause pressure, cramping, or pain. Not every contraction means labor has begun.

Duration

How long a contraction lasts, measured from when the tightening begins until it releases.

Frequency

How often contractions occur, usually measured from the start of one contraction to the start of the next.

Interval

The time between contractions. Some people use this word for frequency, so ask what the speaker means.

Pattern

The overall behavior of contractions, including whether they become more regular, longer, stronger, or closer together.

Intensity

How strong a contraction feels. This is subjective and may change with position, fatigue, and coping methods.

Resting tone

How relaxed or firm the uterus feels between contractions. Persistent firmness or pain deserves prompt clinical advice.

Contraction timer

A tool that records contraction starts, stops, durations, and frequency. Contraction Timer IO can help create this log, but it cannot diagnose labor.

Start time

The moment a contraction becomes noticeable. Consistent tapping matters more than identifying a perfect instant.

End time

The moment the tightening fades and the uterus feels more relaxed.

Early, practice, and established contraction patterns

Patterns can overlap, especially early in labor. A change in contractions is useful information, but symptoms, pregnancy history, travel time, and your care plan also affect when to call.

Braxton Hicks contractions

Practice tightenings that often remain irregular and may ease with rest, hydration, or a change of activity.

False labor

A nonclinical phrase for contractions that do not continue into established labor. The sensations can still be uncomfortable and convincing.

Prodromal labor

Recurring contractions that may feel organized but stop or change without progressing into established labor.

True labor

A common phrase for contractions associated with ongoing cervical change. Only a clinical assessment can confirm that change.

Regular contractions

Contractions arriving in a reasonably consistent rhythm rather than at widely changing intervals.

Irregular contractions

Contractions with changing gaps, durations, or strength. Irregularity does not automatically rule out early labor.

5-1-1

A contraction-timing mnemonic sometimes used in guidance about contacting a birth unit. The supplied sources do not establish its exact thresholds, so follow your care team’s version.

4-1-1

Another timing mnemonic used by some care teams. This glossary does not have a sourced threshold for it, and local instructions vary.

Coupling

A pattern in which contractions appear close together in pairs, followed by a longer rest.

Call your care team instead of waiting for a timing rule if you have heavy bleeding, reduced fetal movement, continuous severe pain, concern about fluid leakage, or an urge to push.

Labor stages and cervical change

Labor stages describe progress, not a fixed schedule. Labor length varies widely, and a contraction log alone cannot tell how dilated or effaced the cervix is.

First stage of labor

The part of labor during which the cervix thins and opens. It includes latent, active, and transition descriptions.

Latent labor

The earlier part of cervical change, when contractions may be mild, variable, or difficult to distinguish from prodromal labor.

Active labor

A phase with continuing cervical change and generally stronger, more organized contractions. Clinical definitions can differ.

Transition

The late part of the first stage, often associated with intense contractions and increasing pressure.

Second stage of labor

The stage from complete cervical opening through the birth of the baby.

Third stage of labor

The stage after the baby is born when the placenta separates and is delivered.

Dilation

The opening of the cervix. It is assessed during a cervical examination rather than calculated from contraction timing.

Effacement

The thinning and shortening of the cervix as the body prepares for birth.

Station

A clinical description of how far the presenting part of the baby has descended in relation to the pelvis.

Urge to push

A strong involuntary feeling of bearing down or rectal pressure. Contact your birth team promptly if this occurs unexpectedly.

Water breaking, discharge, and visible signs

Fluid and discharge can be hard to identify at home. If you suspect your waters broke, note the time, color, odor, and amount, then contact your care team for instructions.

Mucus plug

Thick cervical mucus that helped seal the cervix during pregnancy. It may come away gradually or as one noticeable piece.

Bloody show

Mucus tinged pink, red, or brown as the cervix changes. Heavy or persistent bleeding needs urgent assessment.

Show

A shorter name for mucus or blood-tinged discharge associated with cervical change.

Waters breaking

The everyday phrase for rupture of the amniotic sac. It may feel like a gush or a continuing trickle.

Rupture of membranes

The clinical term for the amniotic sac opening and releasing fluid. It is often abbreviated ROM.

PROM

Prelabor rupture of membranes, meaning the waters break before labor begins.

PPROM

Preterm prelabor rupture of membranes. It requires prompt clinical evaluation because both timing and infection risk matter.

Amniotic fluid

The fluid surrounding the baby in the uterus. Clear fluid is common, but appearance alone cannot confirm what is leaking.

Meconium

A baby’s first stool. Green or brown amniotic fluid may contain meconium and should be reported promptly.

Leaking fluid

Wetness that may come from amniotic fluid, urine, or discharge. A clinician may need to test it.

Crowning

The point during birth when the baby’s head remains visible at the vaginal opening.

Hospital, monitoring, and delivery terms

These terms often appear in phone advice, hospital notes, or birth plans. Ask the clinician to explain how any recommendation applies to your situation.

Triage

The assessment process used to decide how urgently you need care and whether you should be admitted.

Cervical check

An examination used to assess dilation, effacement, cervical position, and the baby’s descent.

Fetal monitoring

Listening to or recording the baby’s heart rate, sometimes alongside uterine activity.

Induction of labor

Medical methods used to start labor when it has not begun on its own.

Augmentation

Medical support intended to strengthen or improve labor that has already started.

Epidural

Pain relief delivered through a small catheter placed near the spinal nerves in the lower back.

GBS

Group B Streptococcus, a bacterium that may affect plans for antibiotics during labor.

VBAC

Vaginal birth after cesarean. Eligibility and monitoring depend on individual history and available clinical support.

Cesarean birth

Birth through surgical incisions in the abdomen and uterus, sometimes called a C-section.

Birth plan

A written summary of preferences for labor, comfort, monitoring, and newborn care. Clinical needs may require changes.

Pregnancy dates, measurements, and history abbreviations

Dating and scan abbreviations provide context for labor decisions. They are estimates or clinical measurements, not predictions of the exact day labor will begin.

Gestational age

How far a pregnancy has progressed using standard pregnancy dating conventions.

EDD

Estimated due date. By convention, an LMP-based EDD is 280 days, or 40 weeks, after the first day of the last menstrual period (ACOG, 2017).

LMP

Last menstrual period. The first day of that period is commonly used as the starting point for pregnancy dating.

AFI

Amniotic fluid index, an ultrasound measurement used to estimate the amount of amniotic fluid.

EFW

Estimated fetal weight, calculated from ultrasound measurements. It is an estimate rather than an exact birth weight.

Nulliparous

A clinical term for someone who has not previously given birth beyond the point used by their medical system.

Multiparous

A clinical term for someone who has previously given birth. Past labor does not guarantee the same pattern this time.

Dating may be revised using ultrasound or fertility-treatment information. Ask which EDD is recorded in your chart rather than recalculating it during labor.