Foetal Abnormalities Flashcards
What is breech presentation? Why is this significant?
When the foetus presents buttocks or feet first (rather than head in cephalic presentation).
It has significant implication in terms of delivery - especially if occurring at term (>37 weeks). Carries a higher perinatal mortality and morbidity largely due to birth asphyxia/trauma, prematurity and an increased incidence of congenital malformations.
What are the types of breech presentation?
Complete (flexed)
- both legs flexed at the hips and knees - sitting cross-legged
Frank (extended) - most common
- both legs flexed at the hip and extended at the knee
Footling
- one or both legs extended at the hip so that the foot is the presenting part
What percentage of babies are breech at 28 weeks and what percentage are breach at term?
20% are breech at 28 weeks
The majority spontaneously revert to cephalic presentation
Only 3% breech at term
What are the uterine risk factors for breech presentation?
Multiparity
Uterine malformations e.g. septate uterus
Fibroids
Placenta praevia
What are the foetal risk factors for breech presentation?
Prematurity Macrosomia Polyhydraminos Twin pregnancy (or higher order) Abnormality e.g. anencephaly
What are the clinical features of breech presentation?
Diagnosis made at 32-35 weeks 9as likely to revert to cephalic before)
Foetal head felt in upper part of the uterus on palpation and irregular mass (buttocks and legs) in the pelvis.
Foetal heart auscultation higher on the maternal abdomen
If not diagnosed until labour - foetal distress, meconium-stained liquor
Sacrum/foot felt through cervical opening on vaginally exam.
What are the differentials for breech presentation?
Oblique lie - diagonally in uterus with head/buttocks in one iliac fossa
Transverse lie - across uterus with head on one side and buttocks other (shoulder usually presenting part)
Unstable lie - presentation changes day to day, more likely if known polyhydraminos/woman is multparous.
What are the investigations for breech presentation?
USS
- can identify the type of breech
- can also reveal predisposing foetal/uterine abnormalities
What are the options for management of breech presentation?
External cephalic version
Caesarean section
Vaginal breech birth
What is external cephalic version?
The manipulation of the foetus to a cephalic presentation through the maternal abdomen. If successful, can attempt a vaginal delivery.
What are the complications of external cephalic version?
Transient foetal abnormalities
More persistent heart problems e.g. foetal bradycardia (rare)
Placental abruption (rare)
When is external cephalic version contraindicated?
Recent antepartum haemorrhage
Ruptured membranes
Uterine abnormalities
Previous C section
When is a c section indicated as management for a breech presentation?
If external cephalic version is unsuccessful, contraindicated or declined by the woman
When is vaginal breech birth indicated in breech?
Patient preference/presentation at labour
What are the contraindications of vaginal breech delivery?
Footling breech (as the feet and legs can slip through a non-fully-dilated cervix and the shoulders and head can then become trapped)
What must be done hen conducting a breech vaginal delivery?
Hands off - putting traction on can cause foetal head extension and cause it to get trapped
Foetal sacrum should be maintained anteriorly by holding the foetal pelvis
Some manoeuvres may be needed if the baby does not deliver spontaneously (flexing foetal knees, Losvett’s manoeuvre, MSV manoevre)
What are the complications of breech presentation?
Cord prolapse (umbilical cord drops down below the presenting part and becomes compressed)
Foetal head entrapment
Premature rupture of membranes
Birth asphyxia (usually secondary to delay in delivery)
Intracranial haemorrhage (rapid compression of the head during delivery)
Define lie.
The relationship between the long axis of the foetus and the mother
Can be longitudinal, transverse or oblique
Define presentation.
The foetal part that first enters the maternal pelvis.
Cephalic vertex presentation is the most common and safes.
Others include breech, shoulder, face and brow
Define position.
The position of the foetal head as it exits the canal.
Usually the head engages occipito-anterior (occipital facing anteriorly).
Others include occipito-posterior and occipito-transverse