Mechanisms Involved In Labour Flashcards
First stage
(LATENT)
Onset of regular co-ordinated uterine contractions with effacement and dial action of cervix
Second stage
(ACTIVE)
From complete dilation of cervix, with descent to f presenting part until birth of baby
Third stage
From birth of baby to delivery of placenta and membranes and control of any bleeding
Labour is…
A complex process
Labour involves…
A combination of hormonal and mechanical interactions between fetal, placental and maternal systems
During labour…
The widest diameter of the fetus, successfully passes through the widest diameter of the pelvis
Descent and engagement…
Occur together
Descent is encouraged by…
•Increased abdominal muscle tone
•Braxton hicks
•Fundal dominance of uterine contractions
•Increased frequency and strength of contractions
As the head descends it…
Moves towards pelvic brim
Engagement is…
When largest diameter of fetal head moves into maternal pelvis
Engagement can be identified by…
Abdominal palpations
Flexion
Chin to chest of the fetal neck
Flexion occurs due to…
Final dominance of uterine contractions exerting pressure down fetal spine, forcing occipital to come into contact with pelvic floor
When fetal neck flexes…
There is a reduction in circumference to 9.5cm, assisting passage through pelvis
Internal rotation
Gutter shape of the pelvic floor allows the head to rotate into an occipto-anterior position
