Normal and abnormal uterine action Flashcards
What are the 3 classifications for abnormal uterine action
Over-efficient uterus *Precipitate delivery *Excessive contraction and retraction Inefficient uterine action * Hypotonic inertia * Hypertonic inertia * Constriction (contraction) ring Cervical dystocia
What is precipitate delivery?
Precipitate delivery refers to a delivery which results after an unusually rapid labor (combined 1st stage and second stage duration is <2hrs) and culminates in the rapid, spontaneous expulsion of the infant.
What are predisposing factors for precipitate labour
Multiparity Strong uterine contractions Small sized baby Relaxed pelvic or perineal floor muscles Roomy pelvis
5 Maternal complications of precipitate labour?
Laceration Hemorrhage from lacerations or hematoma Uterine atony from exhaustion Infection Uterine inversion
4 Fetal complications of precipitate labour?
Intracranial hemorrhage from sudden change in pressure
Asphyxia - lack of resuscitation and placental compressions
Tearing of the umbilical cord
Fetal injury due to falling
How do you manage precipitate labour
◦Hospitalize before due date ◦Inhalation anaesthesia: as nitrous oxide and oxygen is given to slow the course of labour. ◦Tocolytic agents. ◦Episiotomy to prevent lacerations Examine for tears after
What is retraction ring/Bandl’s ring in excessive contraction and retraction
It is the retraction ring that rises up 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.
How does retraction ring/Bandl’s ring present?
Clinical picture: is that of obstructed labour with impending ruptured uterus
How retraction ring/Bandl’s ring diagnosed?
The Bandl’s ring is seen and felt abdominally as a transverse groove that may rise to or above the umbilicus
What is the complication of excessive contraction and retraction?
- In the pirmigravid woman, labour comes to a cease due to exhaustion of the muscles
- In multigravidae retraction continues with progressive thinning of the lower uterine which could cause rupture and hence foetal and maternal compromise
How do you treat excessive contraction and retraction?
Adequate pain relief
Cesarean section
Prophylactic antibiotics
What is hypotonic uterine action/inertia?
The uterine contractions are infrequent, weak and of short duration
What are general predisposing factors for hypotonic uterine action
- Primigravida particularly elderly
- Anaemia and asthenia
- Nervous and emotional as anxiety and fear.
- Hormonal due to deficient prostaglandins or oxytocin as in induced labour
- Improperuseofanalgesics
What are local factors of hypotonic uterine action
- Overdistension of the uterus.
- Developmental anomalies of the uterus e.g. hypoplasia.
- Myomas
- Malpresentation
How do you manage hypotonic uterine action
Induction of labour - oxytocin, amniotomy
VD with instrumentation
Cesarean section if SVD fail, contraindication to oxytocin, fetal distress
What is hypertonic uterine action/inertia?
Uncoordinated uterine action
What are the 2 types of hypertonic uterine inertia?
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
What is the presentation of hypertonic uterine action?
Prolonged labour
More painful and irregular contraction. The pain is felt before and throughout the contractions with marked lower backache.
High resting intrauterine pressure in between uterine contractions detected by tocography
Slow cervical dilatation
Premature rupture of membranes.
Foetal and maternal distress
How do you manage hypertonic uterine action
Pharmacotherapy:
o Analgesic.
o Epidural analgesia may be of good benefit.
Caesarean section is indicated in:
o Failure of the previous methods.
o Disproportion.
o Foetal distress before full cervical dilatation
What are constriction rings / contraction rings / Schroeder’s rings
It is a persistent localised annular spasm of the circular uterine muscles that occurs at any part of the uterus but usually at junction of the upper and lower uterine segments and may appear at any stage during labour
What are some associated factors of constriction rings / contraction rings / Schroeder’s rings
Mal-presentations and mal-positions. Improper use of oxytocin e.g. ◦ use of oxytocin in hypertonic inertia. ◦ IM injection of oxytocin Premature rupture of membrane Premature attempt in instrumental delivery
How do you diagnose constriction rings / contraction rings / Schroeder’s rings
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.
What are 3 possible complications of constriction rings / contraction rings / Schroeder’s rings
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).
How do you manage constriction rings / contraction rings / Schroeder’s rings
- In the 1st stage: Pethidine may be of benefit.
- 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
