Unit II

Abnormal labour, pre-term labour &

obstetrical emergencies

Normal labour

Power

Passage

passenger

Power

Normal - Uterine contraction

Abnormal uterine actiono Uncoordinated uterine actions, Antony of uterus,

precipitate labour, prolonged labour

Rx - Augmentation of labour Medical and surgical induction

Passage

Contracted pelvis –CPD; dystocia

Rx- Obstetrical operation: Forceps delivery, Ventouse, Caesarian section, Destructive operations

Passenger

Abnormal lie, presentation, position compound presentation

Rx – Version

Rx – Obstetrical operation: Forceps delivery, Ventouse,

Caesarian section, Destructive operations

Complications & Emergencies

• Obstetrical emergencies: Obstetrical shock, vasa praevia,

inversion of uterus, amniotic fluid embolism, rupture

uterus, presentations and prolapse cord

Genital tract injuries –Third degree perinea tear, VVF,RVF

Complications of third stage of labour:o Post partum Hemorrhageo Retained Placenta

Manual removal of placenta

• o Uncoordinated uterine actions, Antony of uterus, precipitate labour, prolonged labouro Abnormal lie, presentation, position compound presentation

• o Contracted pelvis –CPD; dystocia• o Obstetrical emergencies: Obstetrical shock, vasa praevia,• inversion of uterus, amniotic fluid embolism, rupture• uterus, presentations and prolapse cord• o Augmentation of labour Medical and surgical induction• o Version• o Manual removal of placenta• o Obstetrical operation: Forceps delivery, Ventouse, Caesarian section, Destructive

operations• o Genital tract injuries –Third degree perinea tear, VVF,RVF• Complications of third stage of labour:• o Post partum Hemorrhage• o Retained Placenta

Etiology, pathopyhsiology and nursing management of

Abnormal Uterine Action

Normal labour

• Coordinated uterine contractions

progressive dilation of Cx (>/1 cm/hr) &

descent of fetal head

Abnormal/disordered/uncoordinated Uterine Action

• Any deviation from normal pattern of uterine

contractions affecting the course of labour –

abnormal uterine action

Incidence:

• 25% in nulliparous

• 10% in multiparous

Classification

Abnormal Uterine ActionNormal polarity Abnormal polarity

(Incoordinate Uterine Action)Hypertonic dyfunction Hypotonic dyfunction(excessive contraction) (uterine inertia – common)

Obstruction(--) obstruction(+)

Precipitate labour tonic uterine contraction & retraction (bandle’s ring) Hypertonic uterus

Classification

Abnormal Uterine ActionNormal polarity Abnormal polarity

(Incoordinate Uterine Action)

Hypotonic Hypertonic dyfunction dyfunction(excessive (uterine inertia) contraction)

Spastic lower uterine segment

Colicky uterus

Asym-metrical Uterine contraction

Constri-ctionring

Gener-alisedTonic Contr-action

Cervical dystocia

Ineffective uterine contraction

Etiology • Physiology of normal labour not fully understood so this

etiology is also obscure• Risk factors• Prevalent in primi esp. in elderly primi• Prolonged pregnancy• Over distension of Ux (twins & fibroid)• Emotional factor (anxiety & stress)• Obesity• Contracted pelvis & malpresentation• Injudicious administration of sedatives, analgesics &

oxytocics• Premature attempt to at vginal / instrumental delivery

Normal uterine contractions• Polarity of the uterus • Normally 2 pacemakers, one is situated at each

cornua of Ux• Uterine pacemakers produce coordinated uterine

contractionsProperties of normal uterine contractions• Diminishes from to bottom of Ux• Starts from pace maker & propagates towards

the lower uterine segment• Duration of it diminishes progressively

Dysfunctional labour• New pacemakers may come up from

anywhere in the uterus in Dysfunctional labour

• Primary Dysfunctional labour – Cx dilates <1cm / hr following a normal latent phase of laboural dilation stops

• Secondary arrest – cervical dilatation stops or slows after the active phase of labour has started normally

Normal uterine activity(contraction)

• Measured by noting

• Measurement done by

• Normal baseline tonus is between 5 to 20 mm of Hg & peak pressure is around 60 mm of Hg (8Kpa)

Basal tone Active (peak) pressure

Frequency

Clinical palpation (inaccurate)

TocodynamometerWith external transducer

Intra uterine pressure catheter (accurate)

HYPOTONIC UTERINE INERTIA (HYPOTONIC UTERINE DYSFUNCTION)

HYPOTONIC UTERINE INERTIA

• Definition The uterine contractions are infrequent,

weak and of short duration; good relaxation in between contractions & intervals are increased

Aetiology• Unknown but the following factors may be

incriminated:• General factors:> Primigravida particularly elderly.>Anaemia and asthenia.> Nervous and emotional as anxiety and fear.> Hormonal due to deficient prostaglandins or

oxytocin as in induced labour.> Improper use of analgesics.

AetiologyLocal factors> Overdistension of the uterus.> Developmental anomalies of the uterus e.g.

hypoplasia.>Myomas of the uterus interfering mechanically with

contractions.>Malpresentations, malpositions and cephalopelvic

disproportion. The presenting part is not fitting in the lower uterine segment leading to absence of reflex uterine contractions.

>Full bladder and rectum.

Types

• Primary inertia: weak uterine contractions from the start.

• Secondary inertia: inertia developed after a period of good uterine contractions when it failed to overcome an obstruction so the uterus is exhausted.

Clinical Picture * Labour is prolonged.* Uterine contractions are infrequent, weak and of short

duration.* Slow cervical dilatation.* Membranes are usually intact.* The foetus and mother are usually not affected apart

from maternal anxiety due to prolonged labour. * More susceptibility for retained placenta and

postpartum haemorrhage due to persistent inertia.* Tocography: shows infrequent waves of contractions

with low amplitude.

Management• General measures> Examination to detect disproportion,

malpresentation or malposition and manage according to the case.

> Proper management of the first stage.> Prophylactic antibiotics in prolonged labour

particularly if the membranes are ruptured.

Management

• Amniotomy:a.Providing that; > vaginal delivery is amenable,>the cervix is more than 3 cm dilatation and > the presenting part occupying well the lower

uterine segment

Management• Amniotomy:b. Artificial rupture of membranes augments the

uterine contractions by: >release of prostaglandins.> reflex stimulation of uterine contractions when

the presenting part is brought closer to the lower uterine segment.

Management

• Oxytocin: Providing that there is no contraindication for it, 5 units of oxytocin (syntocinon) in 500 c.c glucose 5% is given by IV infusion starting with 10 drops per minute and increasing gradually to get a uterine contraction rate of 3 per 10 minutes.

Management• Operative deliverya.Vaginal delivery: by forceps, vacuum or breech extraction

according to the presenting part and its level providing that,

> cervix is fully dilated. > vaginal delivery is amenable.b.Caesarean section is indicated in: > failure of the previous methods. > contraindications to oxytocin infusion including

disproportion. >foetal distress before full cervical dilatation.

HYPERTONIC UTERINE INERTIA (Uncoordinated Uterine Action)

HYPERTONIC UTERINE INERTIA (Uncoordinated Uterine Action)

• Appears in active stage of labour• New pace makers appear all over the uterus• ^ frequency & duration of uterine tone , Cause rise in baseline tone diminish placental

circulation• The myometrium contracts spasmodically &

irregularly• This contraction force neither dilates the cervix

nor pushes the fetus down

Hypertonic dyfunction (uterine inertia) can arise from any of the conditions such as

Spastic lower uterine segment

Colicky uterus

Asym-metrical Uterine contraction

Constri-ctionring

Gener-alisedTonic Contr-action

Cervical dystocia

Ineffective uterine contraction

Etiology

Clinical features• Uterine tonus is elevated• Pain is present before & after contractions

results in fetal hypoxia in labour• Placental abruption in case of high baseline

tone (> 25 mm Hg)• On CTG reduced variability & late

decelaration• Uterine hyper stimulation d/t oxytocics often

associated with fetal tachycardia

ManagementGeneral measures• Examination to detect disproportion,

malpresentation or malposition and manage according to the case.

• Proper management of the first stage.• Prophylactic antibiotics in prolonged labour

particularly if the membranes are ruptured.

Management

Medical measures:• Analgesic and antispasmodic as pethidine.• Epidural analgesia may be of good benefit.Caesarean section is indicated in:• Failure of the previous methods.• Disproportion.• Foetal distress before full cervical dilatation.Specific Mgt in each condition

Spastic lower segment

• Lack of fundal dominace• The pacemakers do not work in rhythm• Reversed polarity• The lower segment contractions are stronger• Inadequate relaxation in between contractions• Basal tone is > 20 mm Hg

Diagnosis • Patient is in agony with unbearable pain referred

to the back• Evidence of dehydration & ketoacidosis• Distension of bladder & retension of urine,

Distension of the stomach & bowel• Premature attempt to bear down• Fetal distress appears early• Abd. Palpation uterus is tender & hardening of

the uterus, palpation of the fetal parts is difficult

Internal examination

• Cx is thik, oedematous, hangs loosely like a curtain

• Cx not well applied to the presenting part• Inappropriate dilation of the Cx• Absence of membranes• Meconium stained liquor may be there

Management

• No place for oxytocin augmentation• C.S done majority• Correct dehydration & ketoacidosis before C.S

CONSTRICTION (CONTRACTION) RING

CONSTRICTION (CONTRACTION) RING(schroeder’s ring)

• Definition* It is a persistent localised annular spasm of the

circular uterine muscles.• It occurs at any part of the uterus but usually at

junction of the upper and lower uterine segments around a constricted part of the fetus

• usually around the neck in cephalic presentation. * It can occur at the 1st, 2nd or 3 rd stage of labour.

AetiologyUnknown but the predisposing factors are:* Malpresentations and malpositions.• PROM• Premature attempt at instrumental delivery* Improper use of oxytocin e.g. > use of oxytocin in hypertonic inertia. >IM injection of oxytocin.

Diagnosis

* The condition is more common in primigravidae and frequently preceded by colicky uterus.

* diagnosis is difficult * The exact diagnosis is achieved only by feeling

the ring with a hand introduced into the uterine cavity.

Diagnosis

• Ring is not felt by abdomen

• Revealed during C.S in 1st stage of labour,

During forceps application in 2nd stage of

labour, during manual removal in 3rd stage of

labour

• Uterus never rupture

Management

Exclude malpresentations, malposition and disproportion.

• In the 1st stage: Pethidine may be of benefit.• In the 2nd stage: Deep general anaesthesia and

amyl nitrite inhalation are given to relax the constriction ring:

• In the 3rd stage: Deep general anaesthesia and amyl nitrite inhalation are given followed by manual removal of the placenta.

Complications

• Prolonged 1st stage: if the ring occurs at the level of the internal os.

• Prolonged 2nd stage: if the ring occurs around the fetal neck.

• Retained placenta and postpartum haemorrhage: if the ring occurs in the 3rd stage (hour- glass contraction).

CERVICAL DYSTOCIA

CERVICAL DYSTOCIA

Definition• Failure of the cervix to dilate within a

reasonable time in spite of good regular uterine contractions.

Varieties• a.Organic (secondary) due to:> Cervical stances as a sequel to previous

amputation, cone biopsy, extensive cauterisation or obstetric trauma.

> Organic lesions as cervical myoma or carcinoma.

Varieties

b.Functional (primary):> In spite of the absence of any organic lesion

and the well effacement of the cervix, the external os fails to dilate.

> This may be due to lack of softening of the cervix during pregnancy or cervical spasm resulted from overactive sympathetic tone.

Managementa. Organic dystocia:> Caesarean section is the management of choice.b.Functional dystocia:Pethidine and antispasmodics: may be effectiveIf head is sufficiently low down with thin rim of

Cx push rim up manually during contraction & go for ventouse

Management

• If Cx is very much thinned out but only half is dilated Duhrssen’s incision

• Duhrssen’s incision at 2 & 10’ clock positions followed by forceps or ventouse

• If medical Mgt fails C.S

Generalised tonic contraction (syn: uterine tetany)

• In this condition, pronounced retraction occurs involving a whole of the ulterus up to the level of internal os.

• Thus there is no physiological differentiation of the active upper segment and the passive lower segment of the uterus.

Generalised tonic contraction (syn: uterine tetany)

• The whole uterus undergoes a sort of tonic muscular spasm holding the fetus inside ( active retention of the fetus) usuallly there is no risk of rupture.

• New pacemakers appear all over the uterus.• Causes : (i) Cephalopelvic disproportion (ii)

injudicious use of oxytocics.

CLINICAL FEATURES

• The patient is in prolonged labour having severe and continuous pain.

• Abdominal examination reveals the uterus to be somewhat smaller in size, tense and tender.

• Fetal parts are neither well defined,nor is the fetal heart sound audible.

• Vaginal examination reveals jammed head with big capt; dry and oedematous vagina.

Treatment• Correction of dehydration and ketoacidosis – by rapid

infusion of ringer’s solution• Antibiotic- to control infection• Adequate pain rellief• Hypercontractility (tachysytole) induced by oxytocics

can be managed by to tocolytics (terbutaline 0.25mg S.C) Oxytocin infusion should be

stopped.• Caesarean delivery is done in majority of the cases

specially when obstruction is suspected.

Precipitate labour

• A lobour is called precipitate when the combined duration of the first and second stage is less than two hours.

• It is common in multiparae and may be repetitive• Rapid expulsion is due to the combined effect of

hyperactive uterine contractions associated with diminished soft tissue resistance.

• Labour is short as the rate of cervical dilatation is 5cm/hours or more for the nulliparous women.

• It is more common in multiparas when there are:

* strong uterine contractions,* small sized baby, * roomy pelvis,* minimal soft tissue resistance.

Aetiology

Maternal risks include :

• (1) extensive laceration of the cervix, vagina and perineum ( to the extent of complete perineal tear)

• (2) PPH due to uterine hypotonia that develops subsequent to unusual vigorous contractions

• (3) Inversion• (4)uterine rupture • 5) infection• (6) Amniotic fluid embolism.

fetal risks

• intracranial stress and haemorrhage because of rapid expulsion without time for moulding of the head.

• The baby may sustain serious injuries if delivery occurs in standing position; bleeding from the torn cord and direct hit on the skull are real hazards.

Treatment• The patient having previous history of precipitate labour

should be hospitalised prior to labour During labour,• the uterine contraction may be suppressed by

administering ether or magnesium sulphate during contractions.

• Delivery of the head should be controlled. Episiotomy should be done liberally.

• Elective induction of labour by low rupture of membranes and conduction of controlled delivery is helpful.

• Oxytocin augmentation should be avoided

EXCESSIVE UTERINE CONTRACTION AND RETRACTION

Physiological Retraction Ring• It is a line of demarcation between the upper

and lower uterine segment present during normal labour and cannot usually be felt abdominally.

Tonic uterine contraction &retraction(Pathological Retraction Ring /Bandl’s ring)

It is the rising up retraction ring during obstructed labour due to marked retraction and thickening of the upper uterine segment while the relatively passive lower segment is markedly stretched and thinned to accommodate the foetus.

* The Bandl’s ring is seen and felt abdominally as a transverse groove that may rise to or above the umbilicus.

* Clinical picture: is that of obstructed labour with impending rupture uterus.

* Obstructed labour should be properly treated otherwise the thinned lower uterine segment will rupture.

Pathological Retraction Ring Constriction Ring

Occurs in prolonged 2nd stage. Occurs in the 1st, 2nd or 3rd stage.

Always between upper and lower uterine segments.

At any level of the uterus.

Rises up. Does not change its position.

Felt and seen abdominally. Felt only vaginally.

The uterus is tonically retracted, tender and the foetal parts cannot be felt.

The uterus is not tonically retracted and the foetal parts can be felt.

Maternal distress and foetal distress or death.

Maternal and foetal distress may not be present.

Relieved only by delivery of the foetus. May be relieved by anaesthetics or antispasmodics.

THE END