Hypertonus uterine inertia

Question 1

etiology

Answer 1

• there are 2 types of Hypertonus uterine inertia
  1. Precipitate Labour – combined duration of 1st & 2nd stage < 2hours.
• Rapid expulsion is due to combined effect of hyper-active uterine contractions
  associated with ↓ soft tissue resistance

2. Tonic Uterine Contraction & Retraction (Syn: Bandl’s ring, Pathological retraction ring)
   - Predominantly due to obstructed labour

Question 2

characteristics

Answer 2

1. Precipitate Labour
   i) Common is multiparae & may be repetitive.
   ii) Labour is short – rate of cervical dilatation 5cm/hour (nulliparous)
2. Tonic Uterine Contraction & Retraction
   a) Pathologic anatomy
   i) Gradual ↑ in intensity, duration & frequency of uterine contraction.
   ii) Relaxation phase → less & less.
   iii) Ultimately a state of tonic contraction develops. Retraction continues.
   iv) Lower segment elongates & → progressively thinner to accommodate
   the fetus driven from from the upper segment.
   v) A circular groove encircling the fetus is formed between the active upper segment & the distended lower segment, called pathological retraction ring (Bandl’s ring).
   vi) Due to pronounced retraction – fetal jeopardy (danger) or even death.
   Primigravidae – further retraction stops in response to obstruction &
   labour comes to a standstill – a state of uterine exhaustion
   - Contractions may restart after a brief period of rest with
   renewed vigour.
   Multiparae – retraction continues with progressive circumferential dilatation & thinning of the lower segment.
   - progressive rise of the Bandl’s ring; moving nearer & nearer to the umbilicus & ultimately, lower segment ruptures.
   b) Clinical features
   i) Patient is in agony – continuous pain & discomfort → restless.
   ii) Features of exhaustion & keto-acidosis are evident.
   iii) Abdominal palpation
3. Upper segment – hard & tender.
   Lower segment – distended & tender.
4. The pathological retraction ring is placed obliquely between the umbilicus & symphysis pubis & rises upwards in course of time.
5. Taut tender round ligaments may be felt on either side.
   - because uterine attachments of the round ligaments have been
   raised by the shortening of the upper segment & distension of the
   lower segment
6. Fetal parts may not be well defined.
7. FHS is usually absent.
   iv) Internal examination
8. Vagina – dry & hot with offensive discharge
9. Fully dilated cervix
10. Membranes are absent
11. Cause of obstructed labour is revealed

Question 3

fetal complications

Answer 3

1.Precipitate Labour
a) Maternal
Extensive laceration of cervix, vagina & perineum (to the extent of complete perineal tear)
Postpartum haemorrhage due to subsequent uterine hypotonia.
Inversion
Infection
Uterine rupture
Amniotic fluid embolism

b) Fetal
i) Intracranial stress & haemorrhage (due to rapid expulsion without time for moulding of the head)
ii) Serious injuries if delivery in standing position
- bleeding from the torn cord & direct hit on the skull.
2. Tonic Uterine Contraction & Retraction
i) Maternal exhaustion & sepsis that appears early
ii) Fetal anoxia & even death are usually early
iii) Rupture of uterus is common in multigravidae.

Question 4

management

Answer 4

1. Precipitate Labour
   - If have previous history of precipitate labour – hospitalized before labour.
   - Elective induction of labour by low rupture of membranes & careful conduction of controlled delivery may be advantageous.
2. Tonic Uterine Contraction & Retraction
   - Relieve the obstruction by safe procedure after excluding ruptured uterus