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.
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.
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
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
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.
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.
33.
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.
39.
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
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