Labour
-
Upload
communitycollegemd -
Category
Health & Medicine
-
view
35 -
download
0
Transcript of Labour
Labour
• Definition: Natural process that culminates in the delivery of one or more infants. Retrospective diagnosis.• Spontaneous onset of labour at term is typically between 37 and 42 weeks.
Passage• Pelvic inlet: Bounded by the sacral
promontory, iliopectineal line and symphysis pubis. Greatest diameter is the transverse plane ~13.5cm.• Pelvic outlet: Bounded by the pubic
arch, ischial tuberosities, tip of the coccyx and the sacrotuberous ligament. Greatest diameter is the AP diameter at 13cm.• Plane of least dimensions: Bounded by
the lower border of the symphysis pubis, the sacrum and the ischial spines.• Once the head has descended past the
ischial spines (i.e. the plane of least dimension), it is possible to deliver vaginally.• VIA: Four types of female pelvis:
arthopoid (narrow transverse, wide AP), gynecoid (wide inlet & outlet), platypoidal (narrow AP, wide transverse) and android (loveheart shaped, narrow inlet & outlet).
Power• Normal = 3 to 5 contractions per 10 minutes• If less, there is slower cervical dilatation.• If more, there is uterine hyperstimulation – this is associated with foetal distress.
Passenger• Lie: Relationship of the long axis of the foetus to the long axis of the mother. [transverse/ longitudinal/ oblique]• Presentation: The foetal pole that lies over the pelvic inlet. [cephalic/ breech/ shoulder]• Attitude: Relation of the foetal head to the spine. [flexed/ extended/ neutral]• Denominator: Fixed bony point on presenting part that describes the position• Position: Relationship of the presenting part to the maternal bony pelvis
Question time!
•What is labour?
•When is labour considered ‘at term’?
•What are the variables of labour?
Question time!
•What is labour?Natural process that culminates in the delivery of one or more infants. Retrospective diagnosis.
•When is labour considered ‘at term’?Spontaneous delivery between 37-42 weeks.
•What are the variables of labour?Passage: Maternal bony pelvis
Power: Uterine contractions (3-5)
Passenger: Foetus
Question time!
•Define foetal lieRelationship of the long axis of the foetus to that of the mother. May be longitudinal, transverse or oblique.
•Define foetal presentationThe foetal pole that lies over the pelvic inlet. May be cephalic, breech or shoulder.
•Define foetal positionThe relationship of the presenting part to the maternal bony pelvis (e.g OA, OP)
First stage• Onset of labour to full cervical dilatation• *** What does cervical dilatation mean?• Two stages:• Latent phase (~8H): Point at which woman perceives regular
uterine contractions until 4cm dilatation. Prolonged if >20H in a nullipara; >16H if multipara.• Active phase (~8H nullipara, 6H multipara): 4cm dilatation to
fully dilated and regular contractions. Rate of dilatation should be >1cm per hour if nullipara; >1.5cm per hour if multipara.
Second stage• Full dilatation to delivery of the baby• Prolonged if >2H in a nullipara and >1H in a multipara. Add 1H if epidural anasthesia is used.• Phases:• 1: Passive descent of head until levator ani is reached• 2: Phase of active pushing.
Third Stage• Delivery of the placenta and membranes.• Normally 5-30 minutes. Prolonged if >1H.• Expectant management of post-partum haemorrhage:• 10IU of IM syntocinon as the anterior shoulder of the baby is
delivered.• Early cord clamping and cutting.• Controlled cord traction.• Fundal massage of uterus.
WARNING:Placenta is the weirdest thing you
will ever see!
•When is labour considered ‘at term’?
•What are the variables of labour?
•What are the stages of labour?
•What is expectant management of PPH?
•When is labour considered ‘at term’?Spontaneous delivery between 37-42 weeks.
•What are the variables of labour?Passage: Maternal bony pelvis
Power: Uterine contractions (3-5)
Passenger: Foetus•What are the stages of labour?
First stage: Onset of labour to full cervical dilatation. Latent phase (regular uterine contractions until 4cm dilatation) and active phase (4cm to full dilatation. 1cm/hour if nulliparous, 1.5 if multiparous.
Second stage: Full dilatation to delivery of baby. Phase 1 (passive descent) and phase 2 (active pushing). Prolonged if >2H nulliparous, >1H multipara.
Third stage: Delivery of placenta and membranes.•What is expectant management of PPH?
10IU IM syntocinon as the anterior shoulder is delivered
Early cord clamping and cutting
Controlled cord traction
Fundal massage of uterus
Typical Vertex Delivery• Descent: Head descends into pelvis• Engagement: Widest part of head has passed below the pelvic inlet with the head in transverse position.• Flexion: Head flexes as it descends below the sacral promontory.• Internal rotation: Head rotates into AP position.• Extension: Inferior border of the symphysis pubis acts as a fulcrum around which the foetal head extends.• Restitution: Head rotates back into transverse plane
Vaginal Exam in Labour• Used to assess cervical dilatation, membranes, station and presenting part of foetus.• Station: Number of cm of the presenting part past the ischial spines. 0 station is at spines, negative numbers are above and positive numbers below.•Membranes: Intact will feel slippery, broken will feel rough.• In a well flexed head, only the triangle shaped fontanelle should be felt.
Question time!•What are the variables of labour?
•What are the stages of labour?
•What are the variables of labour?
•Name four uses for a vaginal exam in labour.
Question time!•What are the variables of labour?
Passage: Maternal bony pelvis
Power: Uterine contractions (3-5)
Passenger: Foetus
•What are the stages of labour?First stage: Onset of labour to full cervical dilatation. Latent & active
Second stage: Full dilatation to delivery of baby. Phase 1 (passive descent) and phase 2 (active pushing).
Third stage: Delivery of placenta and membranes.•What are the variables of labour?
Descent
Engagement
Flexion
Internal rotation
Extension
Restitution•Name four uses for a vaginal exam in labour.
Cervical dilatation
Membranes
Station
Presenting part