Normal Course of First, Seconds Third Stage of Labour

Obstructed labour

Obstructed labour refers to a situation in which the descent of the presentation is arrested due to mechanical obstruction, despite good and efficient uterine contractions.

Obstructed labour is state when there is no advance of the presenting part even there is good established uterine contractions. The obstruction usually occurs at the pelvic brim, but may occur at the outlet eg deep transverse arrest is android pelvis.

Incidence:

Obstructed labour is quiet high (1-2%) in developing countries because the women are relatively short in stature.

Causes

Fault in the passage

Contracted pelvis and cephalopelvic disproportion This is the most common cause of obstructed labour. The fetus may be large in relation to the pelvis, or the pelvis may be contracted.

Cervical dystocia due to prolapse, previous operative scaring, or from carcinoma of the cervix.

Pelvic mass Such as a large ovarian cyst, a large cervical fibroid etc.

Contraction ring of the uterus.

Full bladder and loaded rectum.

Fault in passenger

Abnormal presentation such as shoulder, brow, facepresentation, compound presentation and transverse lie.

Large baby

Locked and conjoined twins

Congenital malformations of the fetus eg hydrocephalus, fetal ascites, double monsters.

Malposition occipito-posterior position

Fault in power

Abnormal uterine contraction.

Diagnosis

A partograph will help to early recognition of obstructed labour. If the labour is slow to progress, careful abdominal and vaginal examination becomes necessary.

Secondary arrest of cervical dilatation and descent of presenting part with large caput, third degree moulding, cervix poorly applied to presenting part, oedematous cervix, ballooning of lower uterine segment, formation of retraction band, maternal and fetal distress

Effects

Effect on the mother:

Immediate

Ehhaustion is due to a constant agonizing pain an anxiety

Dehydration is due to increased muscular activity without adequate fluid intake

Metabolic acidosis is due to accumulation of lactic acid and ketones

Genital sepsis may develop due to repeated vaginal examination and attempted manipulation without taking aseptic precaution, specially after rupture of membranes

Injury to the genital tract includes rupture of the uterus which may be spontaneous in multiparae or may be traumatic following instrumental delivery

Postpartum haemorrhage and shock may be due to isolated or combined effects of atonic uterus or genital tract trauma.

Neglected obstruction will result in rupture of the uterus due to thinning of the lower uterine segment. Trauma to the bladder may occur as a result of pressure from the fetal head during labour or as a result of trauma during delivery

All these lead to an increased maternal morbidity and mortality.

Remote

Genito-urinary fistula or recto-vaginal fistula

Variable degree of vaginal atresia.

Effect on Fetus

Intrauterine asphyxia result from tonic uterine contraction which interferes with the uteroplacental circulation

Acidosis due to fetal hypoxia and maternal acidosis

Intracranial haemorrhage is due to super moulding of the head.

Ascending infection

All these lead to increase perinatal loose.

Sign and symptoms of obstructed labour

The presenting part does not enter the pelvic brim despite good contractions.

Slow descent of presenting part with large caput.

Slow dilatation of the cervix As the presenting part is unable to descent, cervical dilatation is affected and dilatation is slow.

The cervix hangs like an empty sleeve as the presenting part is not applied to it or cervix poorly applied to presenting part.

Early rupture of membranes The uterine contraction exerts pressure on the membranes that are over the cervix, which may result in early rupture.

The uterus moulds itself around the fetus and does not relax properly between pains.

Difficult to assess the fetal part by abdominal examination.

The patient gradually becomes anxious, dehydrated and exhausted.

Rise in pulse rate, respiration and temperature.

There is sign of metabolic acidosis and ketosis.

Formation of bandls ring

Edematous cervix.

Ballooning of lower uttering segment

On vaginal examination, the vagina feels hot and dry and presenting part is high and difficult to accurate assessment of the station of presenting part due to excessive moulding and large caput.

Sign of fetal and maternal distress.

Management

Preventive management

Antenatal: Detection of the factors likely to produce prolonged labour eg Big baby, small women, malpresentation and position.

Intranatal: Continue vigilance, use of partograph and timely intervention of prolonged labour due to mechanical factors can prevent obstructed labour.

Treatment and management during labour

Assessment of the general condition of the mother by taking vital sign, record amount and color of urine.

The mother should be sedated by intramuscular pethidine 75mg or 1mg /kg body weight.

Dehydration and keto-acidos is are to be corrected by rapid infusion of ringers lacted solution; at least one litre is to be given in running drip.

At list 3 litres of fluid are required to correct clinical dehydration.

Acidosis is corrected by intravenous administration of 10 ml 8.4% sodium bicarbonate and to be repeated, if necessary.

Parential Antibiotics should be administered and then repeated.

Blood sample is sent for blood group and cross matching and prepare the blood.

Send a vaginal swab for culture and sensitivity test.

Empty the bladder. Provide psychological support.

Monitor fetal condition by taking FHS hourly and if available continuous monitoring by cardiotocogram.

If the fetus is alive, the cervix is fully dilated and the head is at 0 station or below, deliver by vacuum extraction;

If there is an indication for vacuum extraction and symphysiotomy for relative obstruction and the fetal head is at -2 station:

- Deliver by vacuum extraction and symphysiotomy;

- If the operator is not proficient in symphysiotomy, deliver by caesarean section.

If the fetus is alive but the cervix is not fully dilated or if the fetal head is too high for vacuum extraction, deliver by caesarean section.

If the fetus is dead:

Deliver by craniotomy;

If the operator is not proficient in craniotomy, deliver by caesarean section.

Note: Rupture of an unscarred uterus is usually caused by obstructed labour.

Management after delivery

General condition of the mother should be closely watched and recorded.

Watch operative site for any bleeding

Intake output chart should be maintained strictly.

Good postoperative management should be provided.

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