3rd Stage of Labour Flashcards
What is the definition of 3rd stage of labour (NICE 2023)
The third stage of labour is the time from the birth of the baby to the expulsion of the placenta and membranes
What does retraction and contraction do?
Reduces the size of the uterus and the placental site and simultaneously thickens the uterine wall.
BY the beginning of the third stage what has happened to the placental site?
Has diminished in size by about 75%. This reduction in size continues after the birth of the baby’s trunk and causes the placenta to shear off.
What are the 3 phase of the removal of the placental?
Latent, Detachments, Expulsive.
What is the latent phase?
Delivery of infant until beginning of seperation-placenta free wall thickens (intermittent contractions), minimal thickening of uterine wall over placenta.
What is meant by detachment?
Period of placental separation and detachment from uterine wall, brought about by gradual thickening of the uterine wall over the site of the placental attachment. Myometrium thickens and reduces its surface area (lower edge off placenta). Leads to shearing off, of placenta in that area. Thickening of myometrium gradually rises to the entire placental area has sheared off (normally about 3 minutes).
What is meant by expulsion?
From complete separation to entire expulsion.
* Upper segment contracts strongly.
* Placenta forced to fold on itself.
* Descends into lower segment.
* Then into vagina.
* Gravity and maternal effort, from stimulation of vaginal floor, leads to expulsion of placenta and membranes
What do the umbilical veins carry?
Oxygenated blood from the placenta to the fetus
What do the umbilical arteries carry?
Nutrient depleted deoxygenated blood away from the fetus to the placenta
What is the intervillous space?
Part of the fetal-maternal interfere, where maternal blood enters to provide nutrients and gas exchange
What is the physiology between the separation of the placenta from the uterine wall?
Compression of the placenta causes maternal blood in the intervillous spaces* to be forced back into the spongy layer of the maternal uterine tissue (decidua)
- The vessels become congested and burst. A small amount of blood seeps between the vessels, the spongy layer and placental surface aiding separation. This blood begins the formation of a retroplacental clot.
What does the retraction of the oblique muscle fibres do?
Constrict the blood vessels so that blood does not drain back into the maternal system.
What are the 2 main ways a placenta separates?
Schultze method
Matthew Duncan method
What is the schultze method?
Separation starts in the centre of the placenta and this part descends first
* Retroplacental clot forms which aids separation
* Fetal surface appears first at the vulva with membranes trailing behind, the retroplacental clot is enclosed within the membranes
* Associated with less blood loss(quicker separation)
* Most common (80%
What is the Matthew Duncan method?
Separation at lower edge of placenta.
* Placenta slips down sideways, and the maternal surface appears at the vulva.
* Associated with longer duration, increased blood loss and ragged membranes.
* Less common (20%
After placental expulsion what are the 4 vital mechanisms that come into play to control bleeding at the site of placental atatchment>
- The empty uterus fully contracts and the uterine walls come into apposition.
- The myometrium continues to contract and retract. The interlacing muscle fibres become “living ligatures” constricting the torn blood vessels and sealing them.
- Activation of coagulation and fibrinolytic systems.
- Breastfeeding and skin to skin increase oxytocin production.
What is the package of care involved in the physiological management of third stage?
- no routine use of uterotonic drugs
- no clamping of the cord until pulsation has stopped, or after delivery of the placenta
- delivery of the placenta spontaneously or by maternal effort. [2014, amended2023
What is the package of care involved in the active management of the third stage of labour?
routine use of uterotonic drugs
- cord clamping and cutting of the cord (see recommendation 1.10.14)
- controlled cord traction after signs of separation of the placenta
What are the signs of separation and descent in the physiological 3rd stage?
-fundus rises up and becomes globular
-Bulge just above symphysis pubis
-Gush of blood per vagium
-More cord becomes visible
-Urges to bear down.
-Uterine contractions
-Placenta enters vagina.
What should we do for a physiological 3rd stage?
Upright position i.e bag in toilet, container birthing stool.
* Maternal effort with a contraction.
* Encourage woman to empty bladder.
* Put baby to the breast.
* Oxytocin producing environment.
What is not considered for us to do in the physiological 3rd stage?
- Administration of oxytocic is not considered part of physiological mngt.(unless heavy bleeding).
- Palpation of uterus‘ Fundus fiddling’.
- Touching the cord or apply cord traction.
- Clamping the cord (unless necessary or requested)
What are the observations in the first stage (NICE ‘23)
-Her general physical condition, as shown by her colour, respiration and her own report of how she feels.
-Vaginal blood loss
What should you discuss when discussing the choice of uterotoni for active management?
oxytocin plus ergometrine may be more effective than oxytocin alone at reducing the risk of postpartum haemorrhage
* oxytocin plus ergometrine is advised if there are risk factors which could increase the risk of postpartum haemorrhage
* oxytocin plus ergometrine is more likely to lead to nausea and vomiting compared with oxytocin alone
* oxytocin plus ergometrine is contraindicated in women with severe hypertension, pre-eclampsia, eclampsia, or severe cardiac, hepatic or renal disease. [2023]
With active management how should oxytocin be delivered NICE 23?
For active management after vaginal birth
* administer 10 units of oxytocin (by intramuscular injection)
* 5 units of oxytocin (by intravenous injection, see recommendation 1.10.12)
* or 5 units of oxytocin plus 500 micrograms of ergometrine (by intramuscular injection)
* immediately after the birth of the baby and before the cord is clamped and cut. [2023].