Normal labour and puerperium Flashcards
Three key factors in labour
Powers (contraction)
Passage (pelvis)
Passenger (foetus)
What physiological factors influence the onset of labour?
Rising placental oestrogen production
Rising oxytocin levels
Release of prostaglandins
+ve feedback stretch reflexes of cervix and myometrium
First stage of labour
From the onset of powerful contractions to full dilatation. latent phase-up to 4cm. Active phase- 4cm onwards
Second stage of labour
complete dilatation to delivery of foetus
when is the second stage stage considered prolonged in a) nulliparous b) multiparous women, +/- analgesia?
a) more than 2 hours
b) more than 1 hour
c) + 1 hr for epidural analgesia
Third stage of labour
Delivery of the foetus to expulsion of the placenta and membranes
How and why is the third stage actively managed?
Oxytocin, ergometrine and controlled traction
Reduces primary PPH
Describe the changes that take place in the cervix as part of labour
Dilatation
Shortening
Softening- increased hyaluronic acid, decreased collagen
contractions which start as early as 6 weeks but not usually felt until 2nd/3rd trimester
Braxton Hicks contractions
When is rupture of membranes deemed premature?
if it happens prior to the first stage of labour
when/why is a cervical sweep offered?
To induce labour; if overdue, if PROM, if long-term condition such as diabetes
Describe the normal “lie”. What position does the head engage the pelvis?
Longitudinal cephalic presentation. Transverse, flexed head
When is the presenting part described as being engaged?
When less than 50% of the head is palpable in the abdomen
What are the foetal stations described in relation to?
The ischial spines (0 is the level of ischial spines)
Name the cardinal movements
Engagement Descent of presenting part Head flexion Internal rotation (so that occiput faces pubis) Head extension and crowning External rotation Delivery of anterior shoulder
