Labour and Delivery Flashcards
What are the three stages labour?
> 0-10cm cervical dilation
Full dilation to expulsion of foetus
Expulsion of foetus to expulsion of placenta
Outline the first stage of labour
Cervix dilates from 0-10cm (1cm per hour) and Braxton-Hicks contractions convert into painful rhythmic contractions every 2-3 mins.
Latent phase = 0-3cm dilation
Active phase = 3-10cm dilation
Why do the myometrial fibres not relax during labour?
As relaxation may allow the foetus to move back up the birth canal, so instead the muscles retract
Outline the second stage of labour
Propulsive phase - from full dilatation to presenting part reaching the pelvic floor
Expulsive phase - from reaching the pelvic floor to delivery of the baby
Outline the third stage of labour
Uretine muscles contract tonically to constrict the blood vessels passing between the interlacing fibres; the placenta separates as the placenta bed is constricted down to half its size
What concerns with the foetus may complicate labour?
Macrosomia, multiple pregnancies and abnormal foetal ‘lie’
What is macrosomia?
Increased foetal size associated with maternal diabetes, obesity, previously large babies or prolonged pregnancy
What is meant by a ‘breech presentation’ of a foetus?
Where the foetus’ head is aimed towards the top of the uterus, not the body, which makes delivery difficult
What problems with the vaginal canal may complicate labour?
Contracted pelvis, narrow birth canal, placenta praevia
What is placenta praaevia?
Where the placenta blocks the exit of the birth canal
What problems with contractions can occur which complicate labour?
Uterine inertia, uncoordinated contractions, hypertonic contraction and uterine rupture
What signs indicate foetal distress in labour?
Meconium-stained liquor, foetal heart rate abnormalities (bradycardia/tachycardia, reduced baseline variability and decelerations)
What cardiac signs may indicate foetal distress in labour?
Abnormal baseline rate (tachycardia or bradycardia), reduced baseline variability and decelerations
What complications may arise with the birth of the placenta?
Retained placenta, uterine atony, soft tissue lacerations and uterine inversion all have the potential to cause life-threatening postpartum haemorrhage and maternal shock
