Normal labour Flashcards
What are the three key factors contributing to normal labour?
Power
Passage
Passenger
What do estrogen and progesterone do to the uterus?
Estrogen: contracts uterus
Progesterone: relaxes uterus
Which hormone initiates and sustains contractions?
Oxytocin
What happens to the number of oxytocin receptors towards the end of pregnancy?
Increases
Where is oxytocin produced?
Decidual and extraembryonic fetal tissues and in the placenta
What is the first stage of labour?
Latent phase: up to 3-4 cm dilatation
Active stage: 4-10cm (full) dilatation
What is the second stage of labour?
Full dilatation - delivery of baby
What is the third stage of labour?
Delivery of baby - delivery of placenta and membranes
What happens during the latent first stage of labour?
Mild, irregular uterine contractions
Cervix shortens and softens
May last a few days
What happens during active first stage of labour?
Slow descent of presenting part (usually head)
Contractions become rhythmic and stronger
How long should the second stage of labour last in nulliparous women?
In nulliparous women considered prolonged if it exceeds 3 hours if there is regional analgesia, or 2 hours without
How long should the second stage of labour last in multiparous women?
In multiparous women, the second stage considered prolonged if it exceeds 2 hours with regional analgesia or 1 hour without
How long should the third stage of labour last?
10 minutes but can take 30+
When does removal of placenta under general anesthetic become necessary?
Duration of 3rd stage of labour >1 hour
What options are there for active management of the 3rd stage of labour?
Includes prophylactic administration of oxytocin 10 units
Ergometrine 1ml
Cord clamping and cutting,
Controlled cord traction
Bladder emptying
Injection of oxytocin directly into the cord
What are the properties of Braxton-Hicks contractions?
Irregular
Do not increase in frequency or intensity
Resolve with walking or change in activity
Relatively painless
Do not lead to delivery
What are the properties of true labour contractions?
Contractions are evenly spaced
Time between contractions gets shorter
Contractions increase in intensity and pain
The pain starts low, rises until it peaks, and finally ebbs away
Mothers abdomen will feel hard during a contraction
What cervical changes accompany increasing frequency of contractions?
There is cervical softening, effacement and dilatation
What is an anthropoid pelvis?
There is an oval shaped inlet with large anterio-posterior diameter and comparatively smaller transverse diameter
What is an android pelvis?
Android shaped pelvis has triangular or heart-shaped inlet and is narrower from the front
African-Caribbean women are more at risk of having an android shaped pelvis
What is the most suitable pelvis type for delivery?
Gynaecoid pelvis
What is the normal fetal position for delivery?
Longitudinal lie
Cephalic presentation
Vertex is presenting part
What position should the fetal head engage in?
Occipito-transverse
What position should the baby’s head be when delivered?
Occipito-anterior