3. Meaning
Any deviation of the normal
pattern of uterine
contractions affecting the
course of labour is called
abnormal uterine action
4. Etiology
Advancing age of the mother
Prolonged pregnancy
Over distention of the uterus due to twins
Psychological Factors
Contracted pelvis
Malpresentations
Full bladder
7. Precipitate Labour
Precipitate Labour
Definition:
A labour lasting less than 3 hours
Etiology: More common in multipara when
there are
strong uterine contractions
roomy pelvis
small sized pelvis
minimal soft tissue resistance
8. Complications
Maternal:
Lacerations of the cervix,
vagina and perineum.
Shock.
Inversion of the uterus.
Postpartum haemorrhage:
no time for retraction,
lacerations.
Sepsis due to:
lacerations,
inappropriate
surroundings.
Foetal:
Intracranial haemorrhage
due to sudden
compression and
decompression of the
head.
Foetal asphyxia due to:
strong frequent uterine
contractions reducing
placental perfusion,
lack of immediate
resuscitation.
Avulsion of the umbilical
cord.
Foetal injury due to falling
down.
9. Management
Before delivery
Patient who had previous precipitate labour
should be hospitalized before expected date of
delivery as she is more prone to repeated
precipitate labour.
During delivery
Inhalation anaesthesia: as nitrous oxide and
oxygen is given to slow the course of labour.
Tocolytic agents: as ritodrine (Yutopar) may be
effective.
Episiotomy: to avoid perineal lacerations and
intracranial haemorrhage.
After delivery
Examine the mother and foetus for injuries.
10. EXCESSIVE UTERINE CONTRACTION
AND RETRACTION
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.
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.
Obstructed labour should be properly treated otherwise
the thinned lower uterine segment will rupture.
12. HYPOTONIC UTERINE INERTIA
Definition: The uterine contractions are infrequent, weak and of
short duration
General factors:
Primigravida particularly
elderly.
Anaemia
Nervous and emotional
as anxiety and fear.
Hormonal due to
deficient prostaglandins
or oxytocin as in induced
labour.
Improper use of
analgesics.
Local factors:
Overdistension of the uterus.
Developmental anomalies of
the uterus
Myomas of the uterus
interfering mechanically with
contractions.
Malpresentations,
malpositions and
cephalopelvic disproportion.
The presenting part is not
fitting in the lower uterine
segment leading to absence
of reflex uterine contractions.
Full bladder and rectum
13. Types
Primary inertia: weak uterine contractions from the start.
Secondary inertia: inertia developed after a period of
good uterine contractions when it failed to overcome an
obstruction so the uterus is exhausted.
Clinical Picture
Labour is prolonged.
Uterine contractions are infrequent, weak and of short
duration.
Slow cervical dilatation.
Membranes are usually intact.
The foetus and mother are usually not affected apart from
maternal anxiety due to prolonged labour.
More susceptibility for retained placenta and postpartum
haemorrhage due to persistent inertia.
Tocography: shows infrequent waves of contractions with
low amplitude
15. HYPERTONIC UTERINE INERTIA
Types
Colicky uterus: incoordination of the different parts of the uterus in
contractions.
Hyperactive lower uterine segment: so the dominance of the
upper segment is lost.
Clinical Picture
The condition is more common in primigravidae and characterised
by:
Labour is prolonged.
Uterine contractions are irregular and more painful.
High resting intrauterine pressure in between uterine
contractions detected by tocography (normal value is 5-10 mm
of Hg).
Slow cervical dilatation.
Premature rupture of membranes.
Foetal and maternal distress.
16. Management
General measures: as hypotonic inertia.
Medical measures:
€ Analgesic and antispasmodic as pethidine.
€ Epidural analgesia may be of good benefit.
Caesarean section is indicated in:
€ Failure of the previous methods.
€ Disproportion.
€ Foetal distress before full cervical dilatation
17. CONSTRICTION (CONTRACTION)
RING
Definition
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 3rd stage of
labour.
19. Aetiology
Unknown but the predisposing factors are:
Malpresentations and malpositions.
Clumsy intrauterine manipulations under light
anaesthesia.
Improper use of oxytocin e.g.
use of oxytocin in hypertonic inertia.
IM injection of oxytocin.
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.
20. Management
Exclude malpresentations, malposition and
disproportion.
In the 1st stage: Pethidine may be of benefit.
In the 2nd stage: Deep general anaesthesia is
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 is
given followed by manual removal of the placenta
21. CERVICAL DYSTOCIA
Definition
Failure of the cervix to dilate within a reasonable
time in spite of good regular uterine contractions.
Varieties
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.
22. Complications
Annular detachment of the cervix: the bleeding
from the cervix is minimal because of fibrosis and
avascular pressure necrosis leading to thrombosis
of the vessels before detachment.
Rupture uterus.
Postpartum haemorrhage: particularly if cervical
laceration extends upwards tearing the main
uterine vessels.
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.
