Flashcards in 3rd Stage of Labour Deck (24)
What is the definition of the 3rd stage of labour?
The third stage of labour commences following the complete delivery of the fetus and is complete when the placenta and membranes have been expelled and bleeding is controlled.
When does the 3rd stage of labour commence?
Following complete delivery of the newborn
When does actual separation of the placenta usually begin?
With the contraction that delivers the baby's trunk
What are the three phases of placental detachment and expulsion?
Name and describe the two methods of placental separation
Schultze - looks like an inverted umbrella. Separates from the central area to the borders with inversion. Fetal side appears first with membranes behind
Matthew Duncan - slips from vagina sideways with maternal surface appearing first. Separates unevenly from the borders towards the centre
List THREE signs that the midwife should be alert to signifying the separation of the placenta
-A small gush of blood
-Fundus becomes round and hard and rises above umbilicus
-The cord length will increase
What is the main benefit of leaving the umbilical cord attached to the baby and unclamped until pulsation ceases?
Can allow more iron to enter the baby's circulation which is most beneficial to preterm or asphyxiated babies
Describe an Expectant/Physiological management of the third stage
-Midwife's role is to observe normal physiological processes and encouraging women.
-Woman is active during the process.
-Delayed cord clamping is possible and early skin to skin is easier to achieve.
-Best position would be squatting or semi upright.
-Less chance of nausea and vomiting
-Women are more likely to feel they have had a positive birth experience
Describe an Active management of the third stage
-Oxytocic drug is administered to mother as the anterior shoulder is delivered or ASAP following birth followed by controlled cord traction
-Early cord clamping is compulsory
-Reduces risk of PPH
-Shortens the length of third stage by speeding up and strengthening contractions
-Woman is passive
Name THREE oxytocic drugs and describe their actions
Ergometrine - used to control bleeding after crowning. Administered IV or IM. Effects occur within 1 minute if IV or 3-7 minutes if IM. 500mg is usual dose. Cannot be administered by a midwife
Syntometrine - Syntocinon component causes strong uterine contractions for around 15 minutes. This can then be sustained by the ergometrine component. Administered IM and had to be stored in the fridge
Syntocinon - the drug of choice. 5-10 SI units administered IM and acts within 2-3 minutes. Has the fewest side effects. Stored in the fridge
List EIGHT points to consider following expulsion of the placenta
-Time of delivery documented
-Midwife palpates abdomen to ensure the uterus is well contracted
-Careful examination of vaginal loss
-Vulva and perineum is cleansed and pad in situ
-Soiled linen changed and woman made comfortable
-Placenta and membranes are examined for completeness
-Examination of placenta, estimation of blood loss, perineal trauma and post birth observations all documented
-MUST be happy that Haemostasis has been achieved and full set of observation undertaken BEFORE leaving the room
Over how many milliletres of blood loss is considered excessive?
How long does the 3rd stage last for?
Usually between 5 and 30 minutes but can take up to an hour
What causes the placenta to begin separation?
The sudden emptying of the uterus following delivery of the baby rapidly reduces the surface area of the placental site to an area approximately 10cm in diameter. This reduction in the support base for the placenta leads to compression and shearing of the placenta from the uterine wall
What usually happens to prevent excess blood loss during placental separation?
The placenta is compressed so that blood in the intervillous spaces is forced back in to the spongy layer of the decidua. Retraction of the oblique muscle fibres constricts the blood vessels supplying the placenta so that the blood cannot drain in to the maternal vascular tree
How much blood flows to the uterus once separation is complete?
Between 450 and 700 ml/min
What THREE processes are involved in stopping the blood flow following separation?
Explain how living ligatures help stop blood flow, following separation of the placenta
The tortuous uterine blood vessels are surrounded by the oblique muscles fibres, which retract and act as "living ligatures" and constrict the blood vessels
Explain how pressure helps stop blood flow, following separation of the placenta
Once the placenta has left the upper segment, a vigorous contraction brings the walls of the uterus in opposition, applying pressure to the placental site
Explain how blood clotting helps stop blood flow, following separation of the placenta
There is a transitory increase in the activity of the coagulation system during and immediately after placental separation so that clot formation in the torn blood vessels is maximised. The placental site is rapidly covered by a fibrin mesh
How can attaching the baby to the breast assist with placental separation and the control of bleeding?
By causing a release of oxytocin from the maternal posterior pituitary gland, resulting in contractions of the uterus
Describe what FOUR things the midwife should check for on the expelled placenta
-The number of cord vessels (two arteries and a vein AVA)
-Membranes should be inspected and only have one hole (which the baby was born through
-Amnion should be stripped back from the chorion to the cord insertion to ensure both membranes are present
-Maternal surface should be inspected to make sure all cotyledons are present. Any abnormalities should be noted
Why might cord blood be taken?
If the mother is rhesus negative, blood is taken for haemoglobinopathy investigations