obstructed labour definition, causes, complications and management.

1. OBSTRUCTED LABOUR

2. ▪ Obstructed labour is a type of difficult labour in which the foetal presenting part gets
arrested and impacted in pelvis due to mechanical obstruction despite good uterine
contractions.
•
improved
Incidence –
in western countries, the condition has been practically eliminated due to
obstetrics care.
In developing countries like India incidence of about 1% in hospital statistics.
❑Etiology
Maternal causes
❖ Defect in
power
❖ Defect in the
passage.
Fetal causes

3. Maternal factor
1. Defect in power- constriction ring.
2. Defects in the passage.
❖Bony passage- contracted pelvis (abnormal size and shape of pelvis). Even secondary
contracted pelvis can occur due to osteomalacia or disease of pelvis like TB even in
women with previous vaginal delivery.
❖Soft tissue passage
a) Cervical dystocia ( primary and secondary)
b) Pelvic tumors,uterine fibroids and ovarian tumours.
c) Tumors of pelvic bones, rectum or bladder.
d) Pelvic kidney
e) Sacculation of the uterus.
f) Broad ligament fibroid.
g) Vaginal atresia.
h) The non gravid horn of a bicornuate uterus below the presenting part.

4. Fetal causes
❑Defect in the passenger
▪ Macrosomic fetus (big baby), it is a common cause of unexpected obstructed
labour in multiparous.
▪ Malpositions ( occipito posterior position and deep transverse arrest)
▪ Malpresentations –brow presentation,face presentation ( mentoposterior position),
transverse or oblique lie, compound presentation.
▪ Abnormalities of multiple pregnancy ( locking of twins and conjoined twins).
▪ Fetal anamolies like hydrocephalus,fetal ascitis,fetal chest and abdominal
tumour,sacrococcygeal teratomas and other tumors.

5. ▪ MORBID ANATOMICALCHANGES
Uterus- multipara develop excessive strong pains in an attempt to overcome the
obstruction. This may lead to tonic contractions of the uterus causing retraction ring
( bandl’s ring) at the junction of upper and lower uterine segment.
▪ Untreated or neglected obstruction leads to foetal death ,over distension of the lower
uterine segment and rupture of the uterus.
▪ Bladder: The bladder becomes an abdominal organ and due to compression of urethra
between the presenting part and symphysis pubis, the patient fails to empty the bladder.
▪ The bladder walls get traumatized, which may lead to blood stained urine, a common
finding in obstructedlabor.
▪ The base of the bladder and urethra, which are nipped in between the presenting part
and symphysis pubis, may undergo pressure necrosis. The devitalized tissue becomes
infected and later on may slough off resulting in the development of genitourinary fistula.

6. ❖EFFECTS ON THE MOTHER
❖ immediate:
1) Exhaustion is due to a constant agonizing pain and anxiety.
2) Dehydration is due to increased muscular activity without adequate fluid intake.
3) Metabolic acidosis is due to accumulation of lactic acid and ketones.
4) Genital sepsis is an invariable accompaniment, especially after rupture of the membranes
with repeated vaginal examination or attempted manipulation outside.
5) Injury to the genital tract includes rupture of the uterus which may be spontaneous in
multiparae or may be traumatic following instrumental delivery.
6) Postpartum hemorrhage and shock may be due to isolated or combined effects of atonic
uterus or genital tract trauma. All these lead to an increased maternal morbidity and
mortality. The deaths are due to rupture of the uterus, shock and sepsis with metabolic
changes.
7) Remote: Even if the patient survives, the following legacies may be left behind:
➢genitourinary fistula or rectovaginal fistula
➢variable degree of vaginal atresia.
➢secondary amenorrhea following hysterectomy due to rupture or due to Sheehan’s
syndrome.

7. ▪ EFFECTS ON THE FETUS
1) Asphyxia results from tonic uterine contraction that interferes with the
uteroplacental circulation or due to cord prolapse, especially in shoulder
presentation.
2) Acidosis due to fetal hypoxia and maternal acidosis.
3) Intracranial hemorrhage is due to supermoulding of the head leading to
tentorial tear or due to traumatic delivery.
4) Infection. All these lead to increased perinatal loss.

8. ▪ PREVENTION
❑Antenatal :
detection of the factors likely to produce prolonged labor (big baby, small
women, malpresentation and position).
❑Intranatal:
❑Continuousvigilance,useofpartographandtimelyinterventionofaprolongedlab
or due to mechanical factors can prevent obstructed labor. Failure in
progress of labor in spite of good uterine contractions for a reasonable
period (2–4 hours) is an impending sign of obstructed labor.

9. ▪ ACTUAL TREATMENT: The underlying principles are:
▪ (1) to relieve the obstruction at the earliest by a safe delivery procedure
▪ (2) to combat dehydration and ketoacidosis,
▪ (3) to control sepsis. Preliminaries:
❖ Fluid electrolyte balance and correction of dehydration and ketoacidosis are done by
rapid infusion of Ringer’s solution; at least 1 liter is to be given in running drip. At
least 3 liters of fluid is required to correct clinical dehydration.
❖ A vaginal swab is taken and sent for culture and sensitivity test.
❖Blood sample is sent for group and cross matching and a bottle of blood should be at
hand prior to any operative intervention.
❖Antibiotic: ceftriaxone 1 g IV is administered.
❖ IV infusion, metronidazole is given for anaerobic infection.

10. ▪ Obstetric management:
▪ Before proceeding for definitive operative treatment, rupture of the uterus
must be excluded.
▪ A balanced decision should be taken about the best method of relieving the
obstruction with least hazards to the mother.
▪ There is no place of “wait and watch”, neither is any scope of using oxytocin
to stimulate uterine contraction.

11. ▪ Vaginal delivery:
The baby is invariably dead in most of the neglected cases and destructive
operation is the best choice to relieve the obstruction.
If, however, the head is low down and vaginal delivery is not risky, forceps
extraction may be done in a living baby.
There is no place of internal version in obstructed labor.
After completion of the delivery and expulsion of the placenta, exploration of
the uterus and the lower genital tract should be done to exclude uterine
rupture or tear.

12. ▪ Cesarean section:
▪ If the case is detected early with good fetal condition, cesarean section
gives the best result.
▪ But in late and neglected cases, even if the fetal heart sound is audible,
desperate attempt to do a cesarean section to save the moribund baby more
often leads todisastrous consequences.
▪ Symphysiotomy:
▪ The place of symphysiotomy has to be duly considered in the developing
countries as an alternative to risky cesarean section.
▪ This can be done in a case of established obstruction due to outlet
contraction with vertex presentation having good FHS.