Transverse_Lie_Flashcards
What is ‘foetal lie’?
The term refers to the long axis of the foetus relative to the longitudinal axis of the uterus.
What are the 3 types of foetal lie?
Longitudinal lie (99.7% of foetuses at term), Transverse lie (<0.3% of foetuses at term), Oblique lie (<0.1% of foetuses at term).
What is transverse lie?
An abnormal foetal presentation whereby the foetal longitudinal axis lies perpendicular to the long axis of the uterus.
What are the two types of transverse lie?
Scapulo-anterior (most common, foetus faces towards mother’s back) and Scapulo-posterior (foetus faces towards mother’s front).
How common is transverse lie at term?
One in 300 foetuses are in transverse lie at term.
What are the risk factors for transverse lie?
Previous pregnancies, fibroids and other pelvic tumours, pregnant with twins or triplets, prematurity, polyhydramnios, foetal abnormalities.
How is abnormal foetal lie detected?
During routine antenatal appointments with a midwife during abdominal examination and confirmed by ultrasound scan.
What are the complications of transverse lie?
Pre-term rupture of membranes (PROM), cord-prolapse (20%), compound presentation (rare in the UK).
What is the management before 36 weeks gestation?
No management required; most foetuses will spontaneously move into longitudinal lie during pregnancy.
What is the management after 36 weeks gestation?
Appointment with obstetric medical antenatal team to discuss options: Active management (external cephalic version, ECV) or Elective caesarian section.
What are the contraindications for ECV?
Maternal rupture in the last 7 days, multiple pregnancy (except for the second twin), major uterine abnormality.
What is the success rate of ECV?
Around 50%.
When is elective caesarian section indicated?
When the patient opts for caesarian section, ECV has been unsuccessful or is contraindicated.
What factors influence the decision to perform a caesarian section over ECV?
Perceived risks to mother and foetus, patient preference, previous pregnancies and co-morbidities, patient’s ability to access obstetric care rapidly.
summarise transverse lie
Transverse lie
‘Foetal lie’ is the term which refers to the long axis of the foetus relative to the longitudinal axis of the uterus.
The 3 types of lie are:
longitudinal lie (99.7% of foetuses at term)
transverse lie (<0.3% of foetuses at term)
oblique (<0.1% of foetuses at term)
The incidence of transverse lie is slightly higher than oblique lie. However, the causes and management options are the same for both. Oblique lie is easier to correct because the foetus is closer to longitudinal lie.
Transverse lie is an abnormal foetal presentation whereby the foetal longitudinal axis lies perpendicular to the long axis of the uterus. In real terms, this means the foetal head is on the lateral side of the pelvis and the buttocks are opposite. When in transverse lie, the foetus can be either ‘scapulo-anterior’ (most common) where the foetus faces towards the mother’s back or ‘scapulo-posterior’ where the foetus faces towards the mothers front.
Epidemiology:
Early in gestation, transverse lie is very common. Most have moved to longitudinal lie by 32 weeks.
At term, one in 300 foetuses are in transverse lie.
Risk factors:
Most commonly occurs in women who have had previous pregnancies
Fibroids and other pelvic tumours
Pregnant with twins or triplets
Prematurity
Polyhydramnios
Foetal abnormalities
Diagnosis:
Abnormal foetal lie will be detected during routine antenatal appointments with a midwife during abdominal examination.
Abdominal examination: the head and buttocks are not palpable at each end of the uterus. The foetus can be felt to be lying directly across the uterus.
Ultrasound scan: allows direct visualisation of the foetal lie. Foetal heart rate is also auscultated to assess for distress.
Complications:
Pre-term rupture membranes (PROM)
Cord-prolapse (20%)
If allowed to progress to vaginal delivery, compound presentation may occur. This is extremely rare in the UK.
Management:
Before 36 weeks gestation: no management required. The patient should be informed that most foetuses will spontaneously move into longitudinal lie during pregnancy.
After 36 weeks gestation: the patient must have an appointment with the obstetric medical antenatal team to discuss management options:
Active management: perform external cephalic version (ECV) of the foetus. This can be performed late in pregnancy and even early labour if the membranes have not yet ruptured. ECV should be offered to all women who would like a vaginal delivery. Contraindications include maternal rupture in the last 7 days, multiple pregnancy (except for the second twin) and major uterine abnormality. Success rate is around 50%
Elective caesarian section: this is the management for women where the patient opts for caesarian section or ECV has been unsuccessful or is contraindicated.
The decision to perform caesarian section over ECV will be based on the perceived risks to the mother and foetus, the preference of the patient, the patient’s previous pregnancies and co-morbidities and the patient’s ability to access obstetric care rapidly.
