complicated pregnancy Flashcards
define foetus lie
foetus relative to the longitudinal axis of the uterus.
types of lie
longitudinal lie (99.7% of foetuses at term)
transverse lie (<0.3% of foetuses at term)
oblique (<0.1% of foetuses at term)
define transverse lie
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.
RFs of transverse lie
- 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 of trasnverse lie
- 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 of transverse lie
- 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.
Mx of transverse lie before 36 weeks of gestation
no management required. The patient should be informed that most foetuses will spontaneously move into longitudinal lie during pregnancy.
Mx of tranverse after 36 weeks of gestation
the patient must have an appointment with the obstetric medical antenatal team to discuss management options:
Mx 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.
most commonest explanation for short episodes <40 mins of decreased variability on CTG
foetus is asleep
if decreased variability lasts for more than 40 minutes
start to worry
other causes of decreased variability in foetal heart rate on CTG
- due to maternal drugs (such as benzodiazepines, opioids or methyldopa - not paracetamol)
- foetal acidosis (usually due to hypoxia), prematurity (< 28 weeks, which is not the case here)
- foetal tachycardia (> 140 bpm, again not the case here)
- congenital heart abnormalities.
what does a CTG do
measures fetal heart rate and uterine contractions.
records pressure changes in the uterus using internal or external pressure transducers
what is baseline bradycardia
bradycardia Heart rate < 100 /min
causes of baseline bradycardia
increased fetal vagal tone
maternal beta-blocker use
what is baseline tachycardia
Heart rate > 160 /min
causes of baseline bradycardia
Maternal pyrexia, chorioamnionitis,
hypoxia
prematurity
what is loss of baseline variability
< 5 beats / min
causes of baseline variabiltiy
prematurity
hypoxia
what is early deceleration
Deceleration of the heart rate which commences with the onset of a contraction and returns to normal on completion of the contraction