Iskandar dzulkarnainNurul syuhadah

LABOUR◦ Event that take place in the uterus and birth canal to expel the viable

fetus through the vagina.◦ The onset is painful, regular contractions, more than one every ten

minutes◦ with progressive cervical effacement and dilatation◦ accompanied by descent of the head of fetus.

DELIVERY◦ The expulsion of a viable fetus out of the uterus.

NORMAL LABOUR (EUTOCIA)◦ Labour is consider normal when mature fetus presenting by vertex◦ delivers by natural efforts◦ without prolongation of labour.

DYSTOCIA◦ A difficult labour, which refers to a labour not progressing satisfactorily

with possible undue consequences to mother and fetus.

POWER

PASSAGE

PASSENGER

Refers to fetalRefers to fetal• AttitudeAttitude• LieLie• PresentationPresentation• DenominatorDenominator• PositionPosition

Primary forcePrimary force – – actions of the uterine actions of the uterine musclesmuscles

Secondary forceSecondary force – – involuntary involuntary contraction of contraction of muscles of muscles of diaphragm and diaphragm and anterior abdominal anterior abdominal wall (bearing down wall (bearing down effort)effort)

Formed by the soft tissues covering Formed by the soft tissues covering

the bony pelvis through which the bony pelvis through which the fetus is expelled during the fetus is expelled during labourlabour

*pelvic inlet*pelvic inlet *pelvic cavity*pelvic cavity *pelvic outlet*pelvic outlet

Onsetregular contraction bringing about progressive cervical regular contraction bringing about progressive cervical changeschanges

Duration <12hrs – nulliparous<12hrs – nulliparous <8hrs – multiparous<8hrs – multiparous

1st stage• from onset of labour

to full dilatation of cervix (10cm)

Latent Phase• from onset to

dilatation (3-4cm)• cervix fully effaced• 3-8hrs

Active Phase• end of LP• full dilatation

(10cm)• 2-6hrs• cervix dilates

1cm/hr

2nd Stagefrom full dilatation of

cervix (10cm) to delivery of fetus

Passive Phase• no maternal urge

to push • fetal head is still

high in the pelvis• sagittal suture in

transverse diameter

Active Phaseshould not last - 2hrs in nulliparous- 1hr in multiparous

3rd stagefrom delivery of fetus to delivery of placenta

• more than 30min is considered prolonged

Lightening◦ as the baby settles into lower uterine segment, causing

lowering of the fundal height; a sense of relief for the mother.

Increased vaginal secretion. Cervix become soft and effaced. False labour pain occur with variable frequency.

There are 2 phase:1) Latent Phase: time between the onset of the labour and 3-4cm

dilatation. Lasted between 3-8 hours(lesser in multiparous)a) Uterine contractions

Regular in frequency. 4-5 in 10 min, each contraction may last 40-45s.

b) Show (blood stained mucus discharge) Evidence of start of effacement and dilatation.

c) Effacement of cervix (thinning of cervix: 2.5cm-paperly thin)

d) Dilatation of cervix

2) Active Phase : time between the end of latent phase(3-4cm dilate) until full dilatation(10cm)

There are 2 phases:1) Passive phase - no maternal urge to push and the fetal head is still

relatively high in the pelvis

2) Active second stagea) Accomplished by downward thrust offered by

↑ uterine contractions voluntary contraction of abdominal muscles

b) Bearing down efforts Breath hold; strain down as in defecation desire

c) Descent of the head.

Series of changes in position and attitude that the fetus undergoes during it passage through the birth canal

1. Engagement2. Descent3. Flexion4. Internal rotation5. Extension6. Restitution7. External rotation8. Lateral flexion (Expulsion)

Head normally enters pelvis in the transverse position. Engagement occurred when the widest part of the

presenting part has passed successfully through the inlet. More than two-fifth palpable abdominally, the head is not

engaged.

A continuous movement Brought by:

◦ uterine contraction◦ pressure of amniotic fluid◦ contractions of abdominal muscles

In primigravida – engagement occur before onset of labour, descent continues in the second stage of labour

In multigravida – descent follows engagement

At the beginning of labour, head of fetus is possible for some degree of flexion.

Presenting diameter (11.5cm)

As labour progresses, the head of fetus meet the resistance of lower uterine segment.

Presenting diameter: Occipitobregmatic (9.5cm) Flexion has advantage of

bringing the shortest diameter of the head into descent.

Important factor: Resistance of pelvic floorOcciput rif head is well flexed occiput will be leading point encouraged to rotate anteriorly sagittal suture now lies in AP diameter

Rotates from LOT(Left occipitotransverse (900) /LOA-Left occipitoanterior (450) position to lie under the subpubic arch.

Head now in occipito-anterior (OA) position Shoulders is in left oblique of the brim The internal rotation cause a slight twist in the

neck of the fetus (the head is no longer in direct alignment with the shoulder).

Occiput is below symphysis pubis. 2 forces:

Uterine contraction – posterior & downward Resistance of pelvic floor - upward and forward

The well flexed head now extends and the occiput escapes from underneath the symphisis pubis and distends the vulva.

Crowning◦ That stage of childbirth when the fetal head has negotiated the pelvic outlet and

the largest diameter of the head is encircled by the vulvar ring. Occiput is delivered followed by bregma, brow and

face.

Rotation of the head 45° to restore the position of the head of fetus - to correct the twist in the neck that occurred during internal rotation.

In order to be delivered, the shoulders have to rotate into the direct AP plane(the widest diameter)

External rotation cause rotation of the head 45° towards mother left thigh in the same direction as restitution.

Thereby relationship of head with shoulder is restored.(same alignment)

Shoulders will be in the anterior-posterior position Anterior shoulder is under symphysis pubis, delivers

first and subsequently posterior shoulder. Aided by lateral movement: The rest of the body is born by lateral flexion with

arms folded on the chest and hands under the chin.

A computerised tracing of fetal heart rate pattern and also measure the uterine contraction.Can be used antenatally & during labour able to detect fetus in distressIt reflects any physiological & pathological changes to the heart rate in response to stimuli, the most important which is hypoxia

Basically there are 4 parameters:1)Baseline heart rate : Normally 110 – 150bpm 160 bpm upper limit of normal. <110 bpm = bradycardia (fetal hypoxia) >160 bpm = tachycardia (fetal compromise)

Congenital tachycardia. Maternal and fetal infections. Acute fetal hypoxia. Fetal anaemia.

2)fetal heart rate variability normal baseline indicate normal autonomic

nervous system of the fetal. The range of the normal variability is about

10-25 beats/min Baseline is modified by fetal sleep states and

activity,hypoxia,fetal infection and drugs that supressing the CNS such as opioids and hypnotics.

Fetal heart rate (FHR) acceleration.

Increased baseline FHR at least 15 bpm lasting at least 15 seconds.

Within 20 – 30 minutes CTG, 2 or more accelerations present define as reactive trace.

The importance of accelerations is that there are a good sign for fetal health.

FHR deceleration◦Transient reduction fetal heart rate of 15 bpm or lasting more than 15 seconds.

◦E.g. fetal hypoxia. related to uterine contraction. What happened during uterine

contraction?? Reduction in blood flow to the placenta =>

reduces fetal oxygenation => alter fetal heart rate (decelaration)

However, normal fetus can withstand the temporary reduction in blood flow to placenta (no hypoxia)

-due to sufficient exchange of oxygen

Type 1 deceleration(early deceleration)

Not associated with fetal distress

onset, maximum fall and recovery of FHR are coincident with the onset, peak and end of the uterine contraction

engagement of fetal head =>compression of the fetal head

Pressure on the fetal head leads to increased ICP that elicit a vagal response (parasympathetic).

Type 2 deceleration (late deceleration) onset, maximal decrease, and recovery that are shifted to the right in relation to the contraction

nadir of deceleration lags behind and persist even after the peak of uterine contraction. – fetal distress

Severe deceleration: hypoxia and acidosis are more pronounced

Variable deceleration pattern nadir variable in depth and timing peak of contractionMay be due to the umbilical cord compression.