Download - Abnormal uterine action
ABNORMAL UTERINE ACTION
NAZNEEN VAHORACLINICAL INSTRUCTOR,MTIN,CHARUSAT
BRIEF REVIEW OF NORMAL UTERINE CONTRACTIONS
POLARITY OF UTERUS: When upper segment contracts, lower segment relaxes.
PACEMAKERS: Two pacemakers situated at each cornua of uterus generating the contraction in co-ordinated manner.
PATTERN OF CONTRACTIONS: uterine contraction starts at cornua, propagates towards lower uterine segment with decrease in the duration and intensity of contraction as it moves away from pacemaker.
PARAMETERS OF UTERINE CONTRACTION• BASAL TONE: 5-20mmHg.
• PEAK PRESSURE: around 60 mm Hg pressure
• FREQUENCY OF CONTRACTION Adequate uterine contractions are 1 in 3
minutes lasting for 45 seconds.
DEFINITION
• Any deviation from normal pattern of uterine contractions affecting the normal course of labour is designated as abnormal uterine contraction.
Over all labour abnormalities occur in• 25%nulliparous• 10%multiparous
EXCESSIVE UTERINE CONTRACTION POLYSYSTOLE :contractions more than once
every 2 minutes.
HYPERSTIMULATION: the above in response to oxytocin
TETANIC UTERINE CONTRACTION: single contraction lasting for more than 3 minutes .
HYPERTONIC UTERINE CONTRACTION: Elevated baseline pressure above 20mm Hg.
ETIOLOGYCause is obscure but following conditions are
often associated:Elderly primigravidaeProlonged pregnancyOver distended uterus- twins, fibroidContracted pelvisMalpresentationObesityEmotional factor: anxiety and stressInjudicious administration of sedative,
analgesics, oxytotics
CLASSIFICATION
UTERINE INERTIA
May appear from the beginning of labour or may develop subsequently after variable period of effective contractions.
FEATURES:• Intensity of contractions- decreases• Duration –shortens• Interval – increases• Good relaxation• General pattern maintained
DIAGNOSISPatient feels less pain during contraction Per abdomen: -less hardening of uterus -easily indentable uterine wall -Fetal parts well palpable -Fetal heart rate normalPer vaginal examination -poor cervical dilatation -associated contracted pelvis,
malpresentation, malposition, deflexed head
MANAGEMENTGENERAL MEASURES:Keep up the morale Avoid supine positionEmpty the bladderMaintain hydration
ACTIVE MEASURES:Low rupture of membranes followed by
oxytocin drip in escalating doses until effective uterine contractions set up.
ROLE OF CAESAREN SECTION:-contracted pelvis-malpresentation-fetal or maternal distress
PRECIPITATE LABOUR
Combined duration of 1st and 2nd stage of labour is < 2 hours.
-common in multipara-Due to combined effect of hyperactive
uterine contractions and diminished soft tissue resistance
RISK MATERNAL• Extensive laceration
of cervix, vagina, perineum.
• PPH due to subsequent uterine hypotonia
• Inversion • Uterine rupture• Infection• Amniotic fluid
embolism
FETUS• Intracranial stress
and hemorrhage( as no time for moulding)
• Direct hit on the skull
• Bleeding from Torn cord
TREATMENT• Patient with prior history should be
hospitalized prior to labour.• Elective induction of labour by low rupture
of membranes.• Oxytocin augmentation to be avoided.• During labour the contractions may be
suppressed with ether or magnesium sulphate.
• Liberal episiotomy.• Controlled delivery.
TONIC UTERINE CONTRACTION AND RETRACTION
PATHOLOGICAL ANATOMY OF UTERUS: Contraction increases in intensity ,duration and
frequency with decreased relaxation in between Retraction continues
Progressive thinning & elongation of lower uterine segment
Development of circular groove b/n upper and lower
segment-called BANDL’S RING.
/
In primigravidae further retraction ceases in response to obstruction and labour comes to a stand still-a state of exhaustion.
In multiparae retraction continues with progressive dilatation and thinning of lower uterine segment
Bandl’s ring moves towards the umblicus
Rupture of lower uterine segment
Fetal jeopardy and death
Clinical features• Patient is anxious looking• Features of exhaustion and ketoacidosis• Upper uterine segment is tender and hard• Lower uterine segment distended and
tender• Groove is seen between the two.
TREATMENT• Correction of dehydration & ketoacidosis• Adequate pain relief • Parenteral antibioticsEXCLUDE RUPTURE OF UTERUSCaesarean delivery in majority of cases
ABNORMAL UTERINE ACTION
FEATURES• Hypertonic uterine state • Appear in active stage of labour• New pacemakers appear all over the
uterus • Irregular and spasmodic contraction of
uterus• Increased frequency& duration of
contraction with decreased relaxation in between.
• Rise in the basal tone
Clinical featuresPatient in agony with unbearable paindehydration and ketoacidosisBladder is distended with often retention of
uterine
PER ABDOMEN:Uterine tendernessIncreased uterine contraction with poor
relaxation in betweenPalpation of fetal parts is difficultfetal distress in the form of fetal tachycardia
PER VAGINAL EXAMINATION:• Cervix –poor dilatation • Poor descent • Meconium stained liquor may be present
TREATMENT• Correction of dehydration • Adequate pain relief
• Empty the bladder
• Parenteral antibiotics
SPASTIC LOWER SEGMENT• Fundal dominance is lacking• Reverse polarity • Lower segment contractions are stronger• Inadequate relaxation in b/n the
contractions• Premature bearing down• Cervix loose, oedematus, not well applied
to the presenting part
MANAGEMENT:Most of the patients need to be terminated by
caesarean section
CONSTRICTION RING
Also called Schroeder’s ring.
May appear in all stages of labour.
Localized myometrial contraction forms a ring of circular muscle fibers of the uterus
Situated at the junction of upper and lower segment
Usually around constricted part of the fetus.
CAUSE:• Injudicious administration of oxytocin• Premature rupture of membranes• Premature attempt of instrumental delivery
FEATURES• Maternal condition not affected• Fetal distress may occur • Ring is not palpable during per abdomen• Felt in o first stage during –caesarean sectiono Second stage –forceps applicationo Third stage –manual removal of placenta
Delivery is usually by caesarean section
Ring usually passes of by deepening plane of anaesthesia.
In case of difficulties ring is cut vertically to deliver the baby.
CONSTRICTION RING Localised
incoordinate uterine contraction
Undue irritability of uterus
Usually at the junction of upper and lower uterine segment
Upper segment contracts and retracts with relaxation in between
Lower uterine segment thick and loose
RETRACTION RING• End result of tonic uterine
contraction and retraction• Following obstructed
labour• Always at the junction of
upper and lower uterine segment
• Tonically contracted upper uterine segment
• Lower uterine segment thinned out
CONSTRICTION RING• MATERNAL
condition Always unaffected unless labour is prolonged
• Ring is not felt on per abdomen
• Round ligament not felt
On per vaginal examination ring can be felt usually above head
RETRACTION RING• Maternal exhaustion
and sepsis appear early
• Ring is felt as a groove
Round ligament taut and tender
Can not be felt on per vaginal examination
CERVICAL DYSTOCIA
Failure of progressive cervical dilatation.TYPES:a)Primary b)Secondary
TYPES OF CERVICAL DYSTOCIA
PRIMARYI. First birth when
ext os fails to dilate
II.Rigid cervixIII.Insufficient
uterine contraction
IV.Malpresentation and malposition
SECONDARYI. Excessive
scarring or rigidity of cervix from previous operation or disease
II.Post delivery III.Cervical cancer
MANAGEMENT:If only thin rim of cervix left behind- it is
pushed up manually during contraction
If cervix is thinned out but only half dilated –Duhrssens’s incision is given at 2’oclock and 10 o’clock position followed by forceps or ventouse extraction
GENERALISED TONIC CONTRACTION
Also called uterine tetanyNo physiological differentiation between
active upper segment and passive lower segment.
Pronounced retraction occurs involving whole of the uterus up to the level of internal os.
Whole uterus undergoes a tonic muscular spasm holding the fetus inside
CAUSE:-Cephalopelvic disproportion -obstruction-injudicious use of oxytocics
FEATURES
PER ABDOMINAL EXAMINATION• Uterus is smaller in size, tense, tender• Fetal parts are not palpable• Fetal heart sounds not audiblePER VAGINAL EXAMINATION• Dry and oedematus vagina• Jammed head with a big caput
TREATMENT
• Tocolytic agents for e.g terbutalin 0.25mg S.C.
• Caesarean delivery is done in majority of cases.