Labour stages and failure to progress

• Labour is the sequence of events that ends in the birth of a baby and the placenta. It is usually divided into three stages: first (cervix opens from closed to fully dilated), second (the baby is born) and third (the placenta is delivered). ^[4]
• "Failure to progress" is the common clinical label used when one of these stages stops advancing despite adequate time and effort. It is the leading reason for oxytocin augmentation and for many primary caesarean births.
• Because a cervix can dilate slowly in a healthy woman, modern guidance asks us to look at the whole picture - contractions, cervical change, fetal position and fetal heart rate - before calling it arrest.
• The cure for true arrest is rarely waiting: supportive positioning, fluids and analgesia, rupture of the membranes when appropriate, oxytocin augmentation, and delivery by forceps, vacuum or caesarean if needed.
• Guidelines differ on the details: ACOG treats 6 cm as the start of the active phase, WHO uses 5 to 6 cm, and NICE uses 4 cm with room for slower progress. ^[1][2][3]

By the end of this page you should be able to:

1. Describe the three stages and the latent/active phases of the first stage, and explain how the UK, US and WHO definitions differ.
2. Explain the three Ps (powers, passenger, passage) and how each, when faulty, produces protraction or arrest.
3. Recognise labour delay and labour arrest against the current criteria of NICE, ACOG and WHO, including the partograph.
4. List the first-line supportive measures and the oxytocin augmentation strategy, including how long to persist before diagnosing arrest.
5. Plan an approach for prolonged second stage and for labour in women with a previous caesarean.
6. State when augmentation is unsafe and when operative delivery is needed.

Labour is divided into three stages.

• First stage: from the onset of regular contractions that produce cervical change to full cervical dilatation (10 cm). The first stage is in turn split into a latent phase, when contractions produce slow cervical change up to 4 cm, and an established (active) first stage, when there is progressive dilatation from 4 cm. ^[2]
• Second stage: from full dilatation to the birth of the baby. It is commonly split into a passive phase (full dilation before the mother feels the urge to push or is encouraged to push) and an active phase (active bearing down).
• Third stage: from the birth of the baby to delivery of the placenta and membranes.

NICE defines the latent first stage as time, not necessarily continuous, with contractions and cervical change up to 4 cm, and the established first stage as regular contractions with progressive cervical dilatation from 4 cm. ^[2] ACOG recommends that cervical dilatation of 6 cm be considered the start of the active phase. ^[1] WHO uses the Labour Care Guide, which treats 5 to 6 cm as the point at which the active phase begins, and emphasises individualized assessment rather than a single threshold. ^{[3][8] [7]}

A fourth concept is often added: the active management of labour, an older model in which labour is "diagnosed" at 4 cm, the cervix is expected to dilate at 1 cm per hour on a partograph, and arrest is declared early so that oxytocin and delivery can be offered. Modern evidence has moved away from this rigid view. ^[5][6]

Labour dystocia is common and expensive. In 2022, 32.2% of all births in the United States were caesarean deliveries, and labour dystocia is the most common indication for a primary caesarean, accounting for approximately one-third of all caesarean deliveries. ^[1] Protraction and arrest disorders are associated with an increased risk of adverse maternal and neonatal outcomes, including caesarean delivery, chorioamnionitis, postpartum haemorrhage, fetal acidemia and neonatal intensive care unit (NICU) admission. ^[1]

Globally, the "one-centimetre per hour" rule and early augmentation have been criticised for turning normal slow labour into an indication for surgery. A large systematic review of low-risk women found that the median time to advance by 1 cm in nulliparous women was longer than 1 hour until dilatation reached 5 cm, with markedly rapid progress only after 6 cm. ^[5] The 95th percentiles for both nulliparous and parous women show that some women reach 10 cm despite dilatation rates far below 1 cm per hour for most of the first stage. ^[5] Expecting a minimum of 1 cm per hour throughout the first stage is therefore unrealistic for most healthy women. ^[5]

The WHO partograph and its alert and action lines were built on that old 1 cm per hour idea. A systematic review of the alert line's accuracy found that it does not reliably identify women at risk of adverse birth outcomes, because the percentage of women crossing the alert line varies from 8% to 76% for the outcomes studied and no study showed a robust diagnostic profile. ^[6] This is why the WHO Labour Care Guide was introduced to replace the classical partograph. ^[8]

Failure to progress is rarely a single fault; it is the result of mismatch between the powers, the passenger and the passage (the three Ps, below). Risk factors for protracted or arrested labour include, but are not limited to, nulliparity, a large-for-gestational-age fetus, maternal obesity, advanced maternal age, fetal occiput posterior position and cephalopelvic disproportion. ^[1] Other contributors that should be looked for on the labour ward include:

• Malposition and malpresentation: occiput posterior, transverse, or breech, which lengthen both stages.
• Uterine overdistension: multiple pregnancy, polyhydramnios and macrosomia, which exhaust the myometrium.
• Bony or soft-tissue obstruction: contracted pelvis, cervical oedema or a full bladder.
• Inadequate contractions: poor uterine activity (hypotonic dysfunction) or, less often, incoordinate, painful but ineffective (hypertonic) contractions.
• Psychological factors: fear, lack of support and immobility, which can kettle a normal labour into a stalled one.

Everything about failure to progress can be traced to the three Ps:

1. Powers - the uterine contractions and the maternal pushing. A contraction must peak high enough (about 50 mmHg or more above baseline in the active phase) and recur often enough to pull the cervix up and push the presenting part down. If contractions are too weak, too infrequent, or badly coordinated, dilatation stalls: this is the commonest mechanism and the one most responsive to oxytocin.
2. Passenger - the fetus. Size (especially a large head), attitude, presentation and position all matter. A fetus in the occiput posterior position has a larger presenting diameter and is far more likely to rotate slowly or arrest in the second stage. A brow presentation, a persistent mentum posterior face, an asynclitic head or a tumour (such as a sacrococcygeal teratoma) can make vaginal delivery impossible.
3. Passage - the maternal pelvis and the soft tissues lining the route. The gynaecoid pelvis is the easiest; android, anthropoid and platypelloid shapes restrict different diameters. Soft-tissue dystocia from a full bladder, a distended rectum, a cervical ridge, or dense scarring after cervical surgery also slows or stops descent.

In practice the three Ps combine. For example a slightly large head in an android pelvis with weak contractions: no single cause, but progress stops. Reassessing in terms of powers, passenger and passage is the clinical habit that turns "failure to progress" from a label into a plan.

Labour is recognized by regular, progressive contractions that cause cervical change. Ask about the contraction pattern: frequency, length and intensity; whether the show has appeared; whether the membranes have ruptured; and whether the woman feels an urge to push. Back pain that eases between contractions and then intensifies is common with an occiput posterior position.

• First stage - contractions stop producing cervical change despite several hours of established labour, or the cervix dilates at strikingly less than 1 cm every 2 hours after 6 cm. ^[1]
• Second stage - pushing goes on without descent or rotation of the head, or descent stops after an initial gain.
• Third stage - the placenta does not deliver within the expected time.

• Abdominal examination: symphysis-fundal height against gestational age, liquor volume, lie, presentation, position and descent of the presenting part relative to the pelvic brim.
• Vaginal examination: cervical dilatation, effacement, consistency, position of the cervix; station and position of the head; presence of caput and moulding; pelvic shape and size as far as can be assessed; and whether the bladder is empty. Do not do repeated examinations: vaginal examination is uncomfortable and every examination carries infection risk, particularly after the membranes have ruptured.
• Fetal monitoring: continuous cardiotocography is usually recommended once delay or augmentation is diagnosed, and in any high-risk labour.
• Recording: plot dilatation and station on a partograph or on the Labour Care Guide so that progress, or lack of it, becomes visible.

Two questions must be separated: is this true labour (rather than the latent phase or Braxton Hicks) and, once in true labour, has progress actually stalled? The common mimics are listed below.

• Vaginal examination with dilatation and station, repeated at agreed intervals rather than continuously. NICE advises a vaginal examination 2 hours later when delay in the established first stage is suspected, and diagnosis of delay if progress is under 1 cm. ^[2]
• Cardiotocography (CTG) for fetal heart rate and uterine activity, particularly once augmentation begins.
• Ultrasound when the diagnosis is unclear: presentation, position of the head (occiput position on transperineal or transabdominal scan), and estimated fetal weight can resolve doubts about passenger and position.
• Laboratory tests as clinically indicated: group and save if operative delivery is likely, full blood count if fever or haemorrhage, and urinalysis (a full bladder masquerades as obstruction).
• Partograph or Labour Care Guide: not a test, but a structured record that makes slow progress visible to the whole team.

There is no universal cut-off for progress. The three guidelines most often quoted use different rules; the discrepancies reflect accumulating evidence that healthy women often dilate more slowly than older textbooks allowed.

The aim is to establish that this is true established labour, to identify why progress has stalled using the three Ps, and then to give labour a fair chance with support before considering operative delivery. Most women, including those who appear slow at the start of the active phase, will reach full dilatation if time and support are provided. ^[5]

• Respectful care and positioning: a labour companion, free movement and an upright or lateral position improve comfort and progress; ^[3] supportive measures should be exhausted before any intervention is labelled. ^[7]
• Optimise powers: correct dehydration, empty the bladder, treat pain. Adequate contractions for progress are those strong and frequent enough to produce cervical change. ^[7]
• Amniotomy: NICE advises considering amniotomy when membranes are intact once delay is diagnosed, after counselling that it shortens labour by about an hour and may increase the strength and pain of contractions. ^[2] WHO does not recommend amniotomy alone for prevention of delay. ^[3] They should not be performed casually: combining amniotomy with oxytocin gives most benefit. ^[7]
• Oxytocin augmentation: begin or titrate the lowest effective dose; high-dose regimens are acceptable in nulliparous women, low-dose in multiparous and in women with a previous caesarean. ^[7] Once adequate activity is achieved, do not declare arrest too quickly: many women deliver vaginally when allowed 4 hours, and nulliparous women up to 8 hours. ^[1][7]
• Tachysystole is defined as more than five contractions in 10 minutes averaged over 30 minutes. If it occurs, stop the oxytocin infusion (its half-life is short), turn the woman to the lateral position, give a fluid bolus, and give oxygen if there are fetal concerns; terbutaline given subcutaneously is an option if it persists. ^[7]
• Do not use routine combined early amniotomy with oxytocin as a package in every labour. ^[2]

• Assess the stall again at 4 to 6 hours (8 hours in nulliparous women, where the evidence shows a fall in caesarean from 35.5% to 18% compared with a 4-hour limit). ^[7] Operative delivery is offered for true arrest, for fetal heart rate concerns, or for obstructed labour.
• Second stage: ACOG defines a prolonged second stage as more than 3 hours of pushing for nulliparous women and 2 hours for multiparous women. ^[1] With regional analgesia, NICE allows pushing to be delayed for 1 hour in multiparous and up to 2 hours in nulliparous women if the head is not visible and the urge to push is absent. ^[2]
• Operative vaginal or caesarean delivery when arrest persists or the fetus is distressed; a "failure to progress" label is not by itself a reason to operate if mother and baby are well and some progress continues.
• Diagnosis of delay in the established first stage (NICE): suspect it with cervical dilatation less than 2 cm in 4 hours in a first labour, or less than 2 cm in 4 hours or clear slowing in later labours; women are advised a vaginal examination 2 hours later and delay is diagnosed if progress is less than 1 cm. ^[2]

Posture and mobility, hydrotherapy (water birth where available), breathing and relaxation, continuous labour companion support, modest analgesia, and avoidance of routine supine positioning. ^[3]

• A simple partograph or the Labour Care Guide, used by a trained midwife, is the single cheapest intervention and makes slow progress visible long before it becomes dangerous.
• Respectful maternity care, oral fluids, pain relief and mobility are recommended throughout. ^[3]
• Suspect obstructed labour early in any woman with a high, unengaged head, caput and moulding or rising heart rate; refer urgently for operative delivery rather than increasing oxytocin.
• Catheterise the bladder, correct dehydration and offer analgesia; review the three Ps before declaring arrest.

• Chorioamnionitis from prolonged labour, especially after rupture of membranes.
• Postpartum haemorrhage from uterine atony after a long labour or high-dose oxytocin; risk rises with both higher doses and longer durations of oxytocin. ^[7]
• Uterine tachysystole and fetal heart rate abnormality during oxytocin augmentation. ^[7]
• Uterine rupture in women with a previous caesarean: risk rises with oxytocin augmentation. ^[7]
• Caesarean birth with its own surgical and anaesthetic risks, and implications for future pregnancies.
• Fetal consequences: acidemia, need for resuscitation, and NICU admission. ^[1]

Labour that is slow but progressive is not a failed labour. With the extended time windows now recommended, most women in whom delay is first suspected still achieve a vaginal delivery; in the ACOG data, 74% of nulliparous women and 91% of multiparous women delivered vaginally when augmentation was continued for 2 hours, and 56% and 88% when continued for 4 hours. ^[1] Extending oxytocin to 8 hours in nulliparous women drops the caesarean rate from 35.5% to 18% compared with a 4-hour limit without worsening neonatal outcomes. ^[7] Reassurance, patience and reassessment beat premature operative delivery in well women.

There is no single screening test for failure to progress, but its risk can be reduced:

• Identify the risk factors before and in early labour (nulliparity, large baby, maternal obesity, malposition, previous caesarean) and plan place of birth accordingly.
• Ensure a skilled, respectful birth companion, good hydration and analgesia, mobility and an empty bladder - all of which support normal progress. ^[3]
• Use structured intrapartum monitoring (partograph or Labour Care Guide) so that slow progress is spotted and managed early rather than becoming an emergency.
• Apply intrapartum care that prioritises the lowest effective oxytocin dose and avoids unnecessary intervention. ^[7]

• Nulliparous women: the commonest group to stall, and the group that benefits most from extended time and support. Expect slower early progress; 1 cm per hour is not the norm before 5 cm. ^[5]
• Multiparous women: usually progress faster; new delay in a woman who previously laboured quickly should prompt a search for a new passenger or passage problem, such as malposition or a larger baby.
• Women with a previous caesarean: augmentation is acceptable with careful titration and monitoring, shared decision-making and a unit ready for emergency laparotomy; rates of uterine rupture rise with oxytocin. Avoid augmentation in women with two previous caesareans. ^[7]
• Breech or other malpresentation: augmentation is controversial; ACOG and SOGC guidance suggest considering it cautiously with low contractions, an epidural and proven passage. ^[7]
• Adolescents and older women: adolescents may have a narrow pelvis; advanced maternal age is a risk factor for dystocia and raises caesarean rates.