The document discusses various types of abnormal uterine action during labor including inefficient contractions, hyperactive contractions, and abnormal patterns of contraction. Specific conditions like uterine inertia, hypertonic uterus, constriction rings, and cervical dystocia are described along with their causes, clinical features, and management. Overall the document provides an overview of deviations from normal uterine function during labor and delivery.

1. Abnormal
uterine
action
Prepared by :
Nirsuba Gurung
Assistant Lecturer
MSON

2. Normal uterine action
Normal labour is characterized by
 coordinated uterine contractions(interval gradually
shortens and intensity gradually increases)
 associated with progressive dilatation of the cervix
(Normal labour is associated with cervical dilatation
≥ 1cm hour in a nulliparous woman )
 descent of the fetal head.

3. Polarity of uterus: When upper pole
contracts lower pole relax
Pacemakers : Two pace makers are
situated at each cornua of the uterus
generating contraction in co-ordinated
manner
Pattern of contraction : uterine contraction
starts at cornua and propagate towards
lower uterine segment with decrease in
duration and intensity as it moves away
from the pacemaker

4. Parameter of uterine action
 Basal tone : 5- 20 mm Hg
 Peak pressure : 60 -80 mm Hg
 Frequency of contraction :adequate uterine
contractions are 1 in every 3 mints lasting for
about 45 sec with good relaxation in between

5. Assessment of contraction
 Abdominal palpation
 Tocodynamometer :with the help of external
trasducers
 Intrauterine pressure catheter

6. Abnormal uterine action
 Any deviation of the normal pattern of uterine
contractions affecting the course of labour is
designated as disordered or abnormal uterine
action.

7.  Overall labour abnormalities occur in about
25% of the nulliparous women
 and 10% of multiparous women.

8. Classification of abnormal
uterine activity
 Inefficient uterine activity
 Hypoactive states/uterine inertia
 Hyperactive, incoordinate states
 Hyperactive lower uterine segment
 Colicky uterus
 Constriction ring
 Cervical dystocia
 Overefficient uterine activity
 Precipitate labour
 Tetanic uterine activity

9. ETIOLOGY
 Prevalent in primi with advancing age of the mother
 Prolonged pregnancy
 Over distension of the uterus due to twins and or
ployhydramnios
 Psychologic factor
 Contracted pelvis, malpresentation and deflexed head. All
these lead to ill fitting of the presenting part into the lower
uterine segment. This probably results in inhibition of the
local reflex which is needed to produce effective contraction
of the upper segment.

10.  Full bladder and loaded rectum reflexly inhibit
uterine contraction
 Injudicious administration of sedatives,
analgesics and oxytocics
 Premature attempt at vaginal delivery or
attempted instrumental vaginal delivery under
light anaesthesia.

11. Uterine inertia
Weak ,infrequent ,inefficient uterine action
Uterine contraction: the intensity is
diminished; duration is shortened; good
relaxation in between contractions and the
intervals are increased. General pattern of
uterine contractions of labour is maintained
but intrauterine pressure during contraction
hardly rises above 25mm Hg

12. Etiology
 Elderly primi
 Anemia or other chronic illnes
 Hypertensive state in pregnancy
 Overdistension of uterus such as in twin or
polyhydraminous
 Malpresentation and malposition
 Full bladder
 Uterine fibroid
 Premature induction of labour

13. Types
 Primary inertia :weak uterine contrations from
the begining
 Secondary inertia :interia developed after a
period of good contraction probably as the
result of contracted pelvis as protective
mechanism .

14. Sign and symptom
1.Patient feels less pain and discomfort
during uterine contraction
2.Hand placed over the uterus during uterine
contraction not only reveals hardening of the
uterus before the patient feels pain but the
contraction also outlasts the pain.
3.Uterine wall is easily indentable at the
acme of a pain.
4.Uterus becomes relaxed after the
contraction; fetal parts are well palpable and
fetal hearts rate remains good.

15. Diagnosis
Internal examination reveals;
 Poor dilatation of the cervix
Membranes usually remain intact
Cervix well applied to the presenting
part
 Associated presence of contracted
pelvis, malposition, deflexed head
or malpresentation may be evident.

16. Complication
Effect on mother:
Prolonged labor
Maternal distress, dehydration and
psychological depression
Increased risk for infection
Increased risk of PPH
Subinvolution

17. Fetal complication
Fetal distress if membrane
ruptures early

18. Management
Careful evaluation of the case is to be
done:
 To be sure that the patient is in true
labour
To exclude cephalopelvic disproportion
or malpresentation
To plan out the management protocol

19. Detected in first stage:
Place of caesarean section:
 Presence of contracted pelvis
Malpresentation
Evidences of fetal or maternal
distress

20. Vaginal delivery
General measures:
 To keep up the morale of the patient
 To empty the bowel by enema and bladder by
encouraging the patient to empty at intervals,
failing which catheterization is to be done
 To maintain nourishment by infusion of 5%
dextrose
 Adequate sedation is ensured by intramuscular
Pethidine 100 mg

21. Active measures
 Acceleration of uterine contraction can be brought
about by low rupture of the membranes followed by
Oxytocin drip if not contraindicated. An infusion of 2
unit of Oxytocin dissolved in 500ml 5% dextrose is
started. The drip rate should be slow at first and is to
be gradually increased until effective contractions are
set up. Close watch of the maternal and fetal
conditions and nature of uterine contractions is
mandatory. The drip is to be continued till 1 hour after
delivery; if, however, cervical dilatation remains
unsatisfactory and or fetal distress appears,
Caesarean section is the best alternative.

22. Detected in second stage
If the case is first seen at this stage,
careful evaluation of the case is to be
done to exclude contracted pelvis,
malpresentation and to determine
station of the head in relation to ischial
spines and fetal condition.

23. Place of caesarean
section
In presence of contracted pelvis or
malpresentation where vaginal
delivery is found unsafe and fetal
condition remains good,
caesarean section may be
preferred even at this stage.

24. Vaginal delivery
Head low down – Forceps or ventouse
delivery
Head not sufficiently low down
· Stimulation of uterine contraction by
oxytocin drip or
 Ventouse extraction. Difficult forceps
should be avoided
 Craniotomy – If the baby is dead

25. Third stage
Active management of the
third stage is advocated

26. HYPERTONIC UTERINE
ACTION
 It is defined as either a series of single
contractions lasting 2 minutes or more or
a contraction frequency of five or more in
10 minutes.Uterine hyperstimulation may
result in fetal heart rate
abnormalities, uterine rupture,
or placental abruption

27. Example
Spastic lower uterine segment
Colicky uterus
Asymmetrical uterine contraction
Constriction ring
Generalised tonic contraction
All these states are collectively
called as incordinate uterine action

28. Inco-ordinate uterine action
Strong and painful uterine
contraction
High frequency
Slow cervical dilatation
Two pole of uterus doesn’t functions
rhythmically

29. Clinical feature
 Labour is prolonged.
 Uterine contractions are irregular and more painful.
The pain is felt before and throughout the
contractions with marked low backache often in
occipito-posterior position.
 High resting intrauterine pressure in between uterine
contractions detected by tocography (normal value
is 5-10 mmHg).
 Slow cervical dilatation .
 Premature rupture of membranes.
 Foetal and maternal distress.

30. Management
CPD- C/S
Vital monitoring
I/V therapy
I/O charting
FSH every 15 min
Partograph
Fetal distress-C/S

31. Colicky uterus
 Various parts of uterus contracts independently
Hyperactive lower uterine segment
 Fundal gradient is lost , reverse gradient of the
uterine activity starts from the lower uterine
segment goes toward fundus and cervix

32. CONSTRICTION
(CONTRACTION) RING
 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.
 It can occur at the 1st, 2nd or 3 rd stage of
labour.

34. Aetiology
Unknown but the predisposing factors are:
 Malpresentations and malpositions.
 Premature rupture of membrane
 Premature attempt of instrumental delivery
 Intrauterine manipulations under light
anaesthesia.
 Improper use of oxytocin e.g.
 use of oxytocin in hypertonic inertia.
 IM injection of oxytocin.

35. Diagnosis
 The condition is more common in primigravidae and
frequently preceded by colicky uterus.
 The exact diagnosis is achieved only by feeling the
ring with a hand introduced into the uterine cavity.
Complications
 Prolonged 1st stage: if the ring occurs at the level of
the internal os.
 Prolonged 2nd stage: if the ring occurs around the
foetal neck.
 Retained placenta and postpartum haemorrhage: if
the ring occurs in the 3rd stage (hour- glass
contraction).

36. Management
 Exclude malpresentations, malposition and
disproportion.
 In the 1st stage: Pethidine morphine may be of
beneficial .
 In the 2nd stage: Deep general anaesthesia and amyl
nitrite inhalation are given to relax the constriction ring:
 If the ring is relaxed, the foetus is delivered
immediately by forceps.
 If the ring does not relax, caesarean section is carried
out with lower segment vertical incision to divide the
ring.
 In the 3rd stage: Deep general anaesthesia and amyl
nitrite inhalation are given followed by manual removal of
the placenta

37. Pathological Retraction Ring
(Bandl’s ring)
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.
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.

38. 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 (see later).
Obstructed labour should be properly treated
otherwise the thinned lower uterine segment will
rupture.

40. DIFFERENCE BETWEEN
CONSTRICTION RING AND
RETRACTION RING
CONSTRICTION RING RETRACTION RING
Nature It is a manifestation of localised
inco-ordinated uterine
contraction.
It is an end result of tonic uterine
contraction and retraction
Cause Undue irritability of the uterus. Following obstructed labour
Situation Usually at the junction of upper
and lower segment but may occur
in other places. The position does
not alter.
At the junction of upper and
lower segment. The position
progressively moves upwards
Uterus Upper segment contracts and
retracts with relaxation in
between lower segment remains
thick and loose.
Upper segment is tonically
contracted with no relaxation
The wall becomes thicker, lower
segment becomes distended and
thinned out

41. Maternal
condition
Almost unaffected unless the
labour is prolonged
Maternal exhaustion, sepsis
appear early
Abdominal
Examination
oUterus feels normal and not
tender
oFetal parts are easily felt
oFHS is usually felt
o Uterus is tense and tender
o Not easily felt
o Ring is felt as a groove
placed obliquely
Vaginal
examination
o The lower segment is not
pressed by the presenting part
o Ring is felt usually above the
head
o Features of obstructed labour
are absent
o Lower segment is very much
pressed by the forcibly driven
presenting part
o Ring cannot be felt vaginally
o Features are present
End result o Maternal exhaustion is a late
feature
o Fetal anoxia usually appear late
o Chance of uterine rupture is
absent
o Maternal exhaustion and
sepsis appear early
o Fetal anoxia and even death
are usually early
o Rupture uterus in multi
gravidae is common

42. Clinical feature
 Mother becomes tired and restless due to continue pain
and discomfort
 Features of maternal distress and keto-acidosis
 Abdominal palpation
 Upper segment hard ,uniformly convex and tender
 Retraction ring obliquely placed between umblicus and
symphysis pubis
 Fetal part may not be well defined
 FHS usually absent
 Vaginal examination
 Dry hot vagina with offensive discharge
 Cervix fully dilated
 Causes of obstruction is revealed

43. Management
 Provide supportive therapy
 Analgesic and sedation
 Hydration
 Prophylactic antibiotic
 Definitive treatment
 Destructive surgery if fetus is dead
 Fetus alive-C/S

44. CERVICAL DYSTOCIA
Definition
Failure of the cervix to dilate within a reasonable time
in spite of good regular uterine contractions.

45. Types
 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.
 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 or excessive fibrous tissue .

46. Etiology
 Ineffective uterine contractions
 Malpresentation, Malposition (abnormal
relationship between the cervix and the
presenting part)
 Spasm (contractions) of the cervix

47. Management
 Organic dystocia:
 Caesarean section is the management of choice.
 Functional dystocia:
 Pethidine and antispasmodics: may be effective.
 Caesarean section: if
 medical treatment fails or
 foetal distress developed.

48. GENERALIZED TONIC
CONTRACTION (UTERINE
TETANY)
 In this condition pronounces retraction occurs
involving whole of the uterus upto the level of internal
os. Thus there is no physiological differentiation of
the active upper segment and the passive lower
segment of the uterus. As there is no thinning of the
lower segment, there is no chance of rupture of the
uterus. The uterine contraction ceases and the whole
uterus undergoes a sort of tonic muscular spasm
holding the fetus inside (active retention of the fetus)

49. Causes
 Failure to overcome the obstruction by powerful
contractions of the uterus
 Injudicious administration of oxytocics
 Irritation caused by repeated unsuccessful attempt
of instrumental delivery

50. Clinical Features
The patient is in prolonged labor having
severe and continuous pain. Abdominal
examination revels 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 caput; dry and
oedematous vagina.

51. Management
 Correction of dehydration and keto acidosis: by
rapid infusion of Ringer’s solution
 Antibiotics : To control infection
 Adequate pain relief