Normal labour Flashcards
What are the 3 Ps for a successful birth?
Passage –Birth canal (Bony pelvis, pelvic floor muscles, perineum)
Passenger – Fetus (Presentation & Position)
Power – Uterine contraction and maternal effort
What is the position of the fetus for normal labour?
Vertex presenting (parietal bones of the baby’s skull) and flexed at the neck when entering the pelvis
What are the cardinal movements of labour?
D Engagement and Flexion
E Internal Rotation
S Extension
C Restitution
E External rotation
N Lateral flexion
T Delivery of the baby
What are pro-pregnancy factors?
Progesterone
Nitric oxide
Catecholamine
Relaxin
What are pro-labour factors?
Oestrogens, Oxytocins, Prostaglandins
Prostaglandin dehydrogenase and inflammatory mediators
What is effacement?
gradual thinning, shortening, drawing up of the cervix measured in percentages from 0 to 100%
What is dilatation?
when your cervix opens (dilates) and the opening is measured (up to 10cm)
Explain the cycle of labour
Baby pushes against cervix causing it to stretch
Stretching of cervix causes nerve impulses to be sent to the brain
Brain stimulates posterior pituitary to release oxytocin
Oxytocin causes smooth muscle lining the uterus to contract
(positive feedback loop)
What are the stages of labour?
- Onset to full dilation (latent and active dilation)
- Full dilation until delivery of baby (passive and active phase)
- Delivery of baby until placental delivery (30min with active, 1hr passive)
How is labour progress checked?
PARTOGRAM documents:
- Contraction frequency/strength/duration
- Fetal heart
- Vaginal examination - cervical dilation, presenting part, position, station relative to spines, membrane status, liquor colour, moulding, caput
- Maternal condition - urine output, temperature, blood pressure, heart rate
What is moulding?
fetal skull bones overlap as the head descends through birth canal (mild/severe)
What is caput?
swelling above the fetal skull (mild/severe)
