Learn — Normal labour & delivery

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Active management of third stage of labour (AMTSL)

Active management of the third stage of labour is the bundle offered at every birth to prevent postpartum haemorrhage: a uterotonic within one minute of the baby's birth, delayed cord clamping, controlled cord traction with counter-traction on the uterus, and assessment of uterine tone with massage of a soft uterus. It replaces expectant (physiological) management and cuts the risk of postpartum haemorrhage by roughly 60%, which is why WHO makes it universal rather than selective.

The uterotonic comes first and always: oxytocin 10 IU IM, or slow IV, within one minute of the birth is the drug of choice; heat-stable carbetocin 100 µg IM is an alternative where the cold chain is unreliable, and misoprostol 600 µg orally is used when no injectable is available.
Delayed cord clamping between 1 and 3 minutes after birth is part of the bundle — it raises the newborn's iron stores and lowers the risk of infant anaemia; clamp immediately only if the baby needs resuscitation.
Controlled cord traction (Brandt–Andrews): wait for the uterus to contract, then apply steady traction on the clamped cord downwards and backwards while the other hand presses the uterus upwards above the symphysis. Stop and wait if the cord does not give or the uterus relaxes.
Signs of placental separation: a gush of blood, lengthening of the cord at the introitus, and a uterus that becomes globular, firm and rises in the abdomen.
After delivery of the placenta, check the membranes and cotyledons for completeness, massage the fundus until it is hard, and then assess tone every 15 minutes for 2 hours.
Never apply cord traction without a contracted uterus and without counter-traction — that is how the uterus inverts; never pull on a cord in a woman who has had no uterotonic.
The placenta should be delivered within 30 minutes; beyond that it is retained and needs an intravenous line, a uterotonic and manual removal under anaesthesia.
Sustained uterine massage as routine prophylaxis adds nothing where oxytocin has been given, but massage of a soft uterus is essential; blood loss is measured, not estimated, with a calibrated drape wherever possible.

Partogram and WHO Labour Care Guide

A partograph is the single sheet on which labour is recorded graphically — cervical dilatation and descent plotted against time, together with the fetal heart, liquor, moulding, contractions, drugs and maternal observations — so that slow progress and deterioration are seen at a glance rather than discovered late. The WHO Labour Care Guide (2020) replaces the classic alert-and-action-line partograph: it begins in the active phase at 5 cm, drops the fixed 1 cm/hour line in favour of reference thresholds that differ with parity, and adds a section for supportive care and shared decisions.

The classic WHO partograph plots the cervicogram from 4 cm with an alert line of 1 cm per hour and an action line 4 hours to its right: crossing the alert line means reassess and arrange transfer, crossing the action line means intervene.
Recording frequency in the active first stage: fetal heart every 30 minutes, contractions every 30 minutes (number in 10 minutes and duration of each), pulse every 30 minutes, blood pressure and temperature every 4 hours, urine output and testing every 2–4 hours, and vaginal examination every 4 hours.
Notation: liquor is I (intact), C (clear), M (meconium), B (blood) or A (absent); moulding is 0, +, ++ or +++; contractions are shaded by duration — dots for under 20 seconds, diagonal lines for 20–40 seconds and solid shading for over 40 seconds.
WHO's 2018 intrapartum guidance redefined the active phase as starting at 5 cm and accepted that dilatation slower than 1 cm/hour is not on its own a reason for caesarean; the Labour Care Guide therefore records nothing on the cervicogram before 5 cm.
The Labour Care Guide sets reference thresholds by parity — for example the second stage should not exceed 3 hours in a nullipara or 2 hours in a multipara — and crossing a threshold triggers assessment, not an automatic operation.
When progress stalls, look for the cause in the three Ps: power (inadequate contractions), passenger (malposition, malpresentation, big baby) and passage (pelvis, a full bladder or a loaded rectum) — and correct hydration, bladder and position before augmenting with oxytocin.
The guide also records supportive care: a companion of the woman's choice, pain relief, oral fluids and freedom to move — care that WHO now treats as standard, not optional.
Correct use of a partograph reduces prolonged labour, obstructed labour, ruptured uterus and emergency caesarean, and it is a mandated labour-room record in India's Dakshata and LaQshya programmes.

Fetal skull diameters

The fetal skull diameters are the fixed measurements of the head that decide whether it can pass through the pelvis, and which of them presents depends entirely on the attitude of the head. A fully flexed vertex presents the suboccipito-bregmatic diameter of 9.5 cm, while a brow — the worst attitude — presents the mento-vertical diameter of 14 cm, which cannot deliver vaginally at term.

Suboccipito-bregmatic 9.5 cm — complete flexion, vertex presentation: the favourable diameter of normal labour.
Suboccipito-frontal 10 cm — incomplete flexion, vertex; occipito-frontal 11.5 cm — a deflexed head, as in an occipito-posterior position.
Mento-vertical 14 cm — brow presentation, the longest anteroposterior diameter; a term-sized brow cannot deliver vaginally unless it converts to a face or a vertex.
Submento-bregmatic 9.5 cm — complete extension, face presentation; a mento-anterior face can deliver vaginally but a persistent mento-posterior cannot.
Transverse diameters: biparietal 9.5 cm (the diameter that must pass the brim for the head to be engaged), super-subparietal 8.5 cm and bitemporal 8 cm.
Landmarks: the anterior fontanelle (bregma) is diamond-shaped and closes at about 18 months; the posterior fontanelle (lambda) is triangular and closes at 6–8 weeks. Feeling the posterior fontanelle on vaginal examination means the head is well flexed.
Moulding shortens the presenting diameters by overlapping the sutures and is graded 0 to +++; caput succedaneum crosses suture lines and clears in 24–48 hours, while a cephalhaematoma is limited by suture lines and takes weeks.

Episiotomy

An episiotomy is a deliberate surgical incision of the perineum and the posterior vaginal wall, made at crowning under local anaesthesia, to enlarge the vulval outlet. It is no longer a routine procedure: WHO and RCOG recommend restrictive, selective use, because routine episiotomy does not prevent severe perineal trauma and causes more pain, blood loss and dyspareunia than a spontaneous tear.

Four types: mediolateral (from the midpoint of the fourchette at about 45° towards the ischial tuberosity — the standard in India), median or midline (straight back towards the anus), lateral (abandoned, because it bleeds and injures Bartholin's duct) and J-shaped.
The median incision heals better, bleeds less and is easier to repair, but it extends into the anal sphincter far more often; the mediolateral is preferred precisely because it keeps the incision away from the sphincter.
Indications: a rigid or scarred perineum, an anticipated tear, shoulder dystocia, instrumental delivery, breech delivery, a big baby, occipito-posterior delivery, and fetal distress where delivery must be hastened — never as a routine.
Technique: infiltrate 5–10 mL of 1% lignocaine (or top up the epidural), and cut at the height of a contraction at crowning, when 3–4 cm of the head is visible, with two fingers protecting the fetal head.
Structures cut in a mediolateral episiotomy: vaginal epithelium, the transverse perineal and bulbospongiosus muscles, part of the pubococcygeus, fascia and perineal skin.
Repair in three layers after a swab and needle count: the vaginal mucosa by a continuous suture started above the apex, the muscle layer by interrupted sutures, and the skin by a subcuticular suture, using polyglactin 2-0 or 3-0; a rectal examination at the end confirms that no suture has passed into the rectum.
Perineal tear grades: first degree involves skin and vaginal mucosa only; second degree involves the perineal muscles; third degree involves the anal sphincter (3a under 50% of the external sphincter, 3b over 50%, 3c the internal sphincter as well); fourth degree involves the anal epithelium. Third and fourth degree tears are repaired in theatre by a trained operator, with antibiotics and laxatives afterwards.
Complications: bleeding — a bleeding episiotomy is a common cause of postpartum haemorrhage with a well-contracted uterus — vulval haematoma, infection and wound breakdown, dyspareunia, and extension into a third or fourth degree tear.

Labour stages and cardinal movements

Labour is the series of events by which the products of conception are expelled from the uterus after viability — regular painful uterine contractions with progressive effacement and dilatation of the cervix and descent of the presenting part. It is described in four stages, and within them the fetus performs seven cardinal movements that present the smallest diameters of the head to each plane of the pelvis.

First stage — from the onset of true labour to full dilatation: a latent phase up to 5 cm, which may be long and irregular, and an active phase from 5 cm to 10 cm in which the slowest normal dilatation is about 1 cm per hour. It lasts roughly 8–12 hours in a nullipara and 6–8 hours in a multipara.
Second stage — from full dilatation to the birth of the baby, with a passive descent phase and an active pushing phase: up to 3 hours in a nullipara and 2 hours in a multipara, an hour longer with an epidural.
Third stage — from the birth of the baby to delivery of the placenta and membranes: normally 5–15 minutes, abnormal beyond 30 minutes, and actively managed with a uterotonic within one minute, delayed cord clamping and controlled cord traction.
Fourth stage — the first one to two hours after the placenta, when atonic haemorrhage is most likely: check fundus, lochia, pulse and blood pressure every 15 minutes.
The seven cardinal movements are engagement, descent, flexion, internal rotation, extension, restitution with external rotation, and expulsion. Engagement means the biparietal diameter has passed the pelvic brim; internal rotation brings the occiput anteriorly under the symphysis; the head is then born by extension around the pubic arch.
True labour has regular contractions that increase in frequency, duration and intensity, felt from the back radiating to the front, with a show and progressive cervical change, and is not relieved by sedation. False labour has irregular contractions felt in front, no show, no cervical change, and settles with rest.
Contractions in established labour come 3 to 5 in 10 minutes and last 40–60 seconds with a relaxed uterus between them; more than 5 in 10 minutes is tachysystole and the oxytocin must be stopped.
Intrapartum monitoring: in the active first stage the fetal heart every 30 minutes (auscultate for a full minute after a contraction), contractions and pulse every 30 minutes, blood pressure and temperature every 4 hours and vaginal examination every 4 hours; in the second stage listen after every contraction or at least every 5 minutes.

Cardiotocography (CTG) — baseline, variability, accelerations and decelerations

Cardiotocography records the fetal heart rate and the uterine contractions on one strip so that the heart’s response to each contraction can be read: an ultrasound transducer over the fetal heart traces the rate and a tocodynamometer over the fundus traces the contractions, on paper running at 1 cm per minute. It is a screening test for fetal hypoxia in labour — a normal trace is strongly reassuring, while an abnormal one is common and often benign, so FIGO (2015) and NICE NG229 (2022) grade the whole trace as normal, suspicious or pathological rather than acting on a single feature.

The baseline is the mean rate over 10 minutes, ignoring accelerations and decelerations, and is normal at 110 to 160 beats per minute: above 160 for more than 10 minutes is fetal tachycardia (maternal fever, dehydration, chorioamnionitis, salbutamol or terbutaline, early hypoxia) and below 110 is bradycardia (maternal hypotension, cord compression, beta-blockers, fetal heart block, a post-term fetus, late hypoxia).
Variability is the width of the band the baseline swings in, normal at 5 to 25 beats per minute and the single best sign of a well-oxygenated fetal brain; under 5 for more than 50 minutes (reduced), over 25 for more than 30 minutes (saltatory) or a sinusoidal shape are abnormal — but the fetus sleeps in cycles of up to 40 to 50 minutes in which variability drops and then recovers, so the clock matters.
An acceleration is an abrupt rise of at least 15 beats lasting at least 15 seconds (10 beats and 10 seconds before 32 weeks); two in 20 minutes make a reactive non-stress test, and their presence means the fetus is not acidotic — their absence on an otherwise normal trace in labour is of uncertain meaning and is not on its own a reason to intervene.
Early decelerations mirror the contraction — they begin with it, reach their lowest point at its peak and recover as it ends, are shallow and keep their variability — and are the vagal response to head compression in the late first and the second stage; they do not mean hypoxia.
Late decelerations begin more than 20 seconds after the contraction has started, reach their lowest point after its peak and return to the baseline only after it has ended, with a gradual U-shaped fall of over 30 seconds; they mean uteroplacental insufficiency — hypotension after an epidural, aortocaval compression on the back, oxytocin hyperstimulation, pre-eclampsia, abruption — and repeated late decelerations with reduced variability are the picture of a fetus becoming acidotic.
Variable decelerations are V-shaped: an abrupt fall (under 30 seconds from onset to the lowest point) of varying depth and duration with no fixed relation to the contraction, from cord compression; most are harmless, but one lasting over 60 seconds, losing its variability, returning slowly or losing its shoulders is a complicated variable deceleration and is read like a late one — the classical rule of 60s adds a depth over 60 beats or a nadir below 60.
A prolonged deceleration lasts more than 3 minutes; one over 5 minutes with the rate below 80 and reduced variability is acute hypoxia — cord prolapse, placental abruption, uterine rupture or hyperstimulation until proved otherwise — and calls for birth, not for more monitoring.
A sinusoidal pattern is a smooth, regular, wave-like baseline of 5 to 15 beats’ amplitude at 3 to 5 cycles a minute lasting over 30 minutes with no accelerations: severe fetal anaemia (Rh isoimmunisation, fetomaternal haemorrhage, ruptured vasa praevia, twin-to-twin transfusion) or acute hypoxia; a bumpier pseudo-sinusoidal trace for under 30 minutes after pethidine or with thumb-sucking is benign.
FIGO (2015) grades the whole trace: normal is a baseline of 110 to 160, variability of 5 to 25 and no repetitive decelerations (repetitive means with more than half the contractions); pathological is a baseline under 100, reduced or increased variability or a sinusoidal pattern, repetitive late or prolonged decelerations for over 30 minutes (20 minutes when variability is reduced), or one prolonged deceleration over 5 minutes; anything in between is suspicious, and NICE NG229 uses the same three words.
Intrauterine resuscitation for a suspicious or pathological trace, in order: turn her onto her left side, stop the oxytocin (and remove any vaginal prostaglandin), give a crystalloid bolus if she is hypotensive, examine vaginally to exclude cord prolapse and check progress, and consider terbutaline 250 micrograms subcutaneously for hyperstimulation — calling the obstetrician as the first step is taken. Oxygen by mask is still widely taught, but NICE NG229 (2022) advises against giving the mother oxygen solely to resuscitate the fetus.

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