Flashcards in Lecture 11 Deck (30)
What is childbirth?
It is is the process whereby the baby and the PLACENTA are expelled from the uterus.
When does childbirth normally occur?
Between 37 and 42 weeks gestation. The first 12 weeks of the pregnancy is the assembly line, from 12 weeks onwards everything else needs to be developed further and to mature.
Where does childbirth tend to occur?
In a hospital. Less than 1% is born at home.
Describe Mrs Jones clinical case?
Mrs Jones feels that the baby is coming. Her midwife is stuck in traffic, her midwife told her that a junior doctor is coming.
What is required for natural childbirth?
1. Use your eyes. An abdominal tumour is rare in women under the age of 45, the best guess of a swollen stomach is a pregnancy.
2. Use your hands. To feel soft parts, bony parts (no tumour is like this). Can establish the fetal lie, also the gestational age (fundal height is measured in centimetres from the pubic symphysis to the top most portion of the uterus. You can also establish presentation. Can also establish engagement (if the babies head can get into the bony pelvis).
3. Use your ears. You can hear fetal heart rate - around 150/160bpm (use a doppler).
4. Use your mouth. Ask the mother for the baby’s movements - happy baby if moving.
What is the fetal lie?
The relation of the long axis of the baby to the uterus - can be longitudinal, transverse and oblique.
What is presentation?
It is the part of the foetus that occupies the lower segment of the uterus: cephalic (vertex), breech (4%), shoulder (<1%).
What is engagement?
Refers to how deep the presenting part is engaged in the bony pelvis - started to come down in preparation for delivery.
When would you do a vaginal delivery?
1. Fetal lie = longitudinal.
2. Presentation = cephalic/breech (?).
3. Engagement = yes.
When would you do a cesarean delivery?
1. Fetal lie = transverse/oblique.
2. Engagement = no.
How do you know if childbirth has started?
Childbirth has started when painful uterine contractions have started and accompany dilatation (cervix is open) and effacement (cervix most of the time is closed) of the cervix. This is known as labour. [EXAM QUESTION].
What are the stages of labour?
1. Cervix opens to full dilation.
2. From full dilatation to delivery.
3. Lasts from the delivery of the baby to the delivery of the placenta.
These stages require progress from each stage.
What is progress of labour determined by?
Three mechanical factors:
1. Passenger - diameter of the baby’s head.
2. Passage - dimension of the pelvis.
3. Power - degree of force to expel the baby.
Describe the mechanical factor passenger?
1. Presenting part - The baby’s head is the largest part to negotiate the birth canal. The head is not round, and the bones are not yet fused (in-between the bones is elastic connective tissue - sutures and where sutures come together are called fontanelles).
2. The second thing that is important is the position of the head (the degree of rotation of the head). If your head is transverse you will fit into the entry of the pelvis (important at the beginning of labour that the baby’s head goes in transverse however when in in the bony pelvis the baby needs to turn).
3. Attitude - the degree of flexion of the head (ideal = maximal flexion; smallest diameter (9.5cm). Extension results in larger diameter - extension 90 degrees = brow (13cm - diameter gets bigger) and extension of 120 degrees = face. Advantage if you are born maximally flexed as it is the smallest diameter. If the baby’s head is maximally flexed you will find the occiput right in the middle. If the baby’s head is not flexed you will find the occiput on the side, and if the baby’s head is the wrong way around the occiput is on the other side (backside).
What are fontanelles and sutures of the head?
1. Sagittal suture - this separates 2 parietal bones.
2. Anterior fontanelle - bordered by 2 frontal and 2 parietal bones.
3. Posterior fontanelle - bordered by 1 occipital and 2 parietal bones.
Where the 3 sutures come together is the occiput.
What is the occiput?
It is the point of reference for where the baby’s head is. You have to do a vaginal examination in order to feel how deep the baby’s head has already advanced. If you can feel 3 sutures coming together it is the occiput. Can determine the occiput - the position of the occiput determines the progress.
Describe the mechanical factor passage?
The bony pelvis - the inlet of the pelvis has a wider transverse diameter. The outlet of the pelvis is wider in the AP diameter. That is why you need to move your head around (carefully take the turn. In the lateral wall of the mid cavity, bony prominences called ischial spines are palpable. The ischial spines are reference points - by which to assess the descent of the head of vaginal examination, the level of descent is called station (-2, -2, 0, +1, +2). If the baby’s head stays above the ischial spines then C-Section has to occur - this is if the baby’s head is above station 0.
Describe the mechanical factor power
Once labour is established the uterus, under the influence of oxytocin, contracts for 45-60seconds every 2-3 minutes = these are regular painful contractions.
Describe normal labour?
It starts with contractions, and these contractions become powerful, this will cause the effacement of the cervix.
Describe the first stage of normal labour?
This is the onset to full cervical dilation. Contractions are regular painful contractions. There is effacement of the cervix. Dilatation (latent phase - first 3cm dilatation) will occur at a rate of 1cm/hour (nulliparous) and 2cm/hour in multiparous women. Descent, flexion and internal rotation will occur at varying degrees. Rupture of the membranes is relate of liquor.
Describe the second stage of normal labour?
From full cervical dilation to delivery. Contractions are still regulate and painful. Descent, flexion and internal rotation are complete. There is the passive stage: where the till head reaches pelvic floor and mother experiences the desire to push. Then there is the active stage: this is irroestiable desire to bear down (40-60 minutes in nulliparous and 20-30 minutes in multiparous).
Describe the delivery stage of normal labour?
As the baby’s head reaches the perineum, it extends to come out of the pelvis (tear, episiotomy): crowds and is born. The head then restitutes rotating 90 degrees to adopt the transverse position in which it entered the pelvis again. The anterior shoulder comes under the symphysis first.
Describe the third stage of normal labour?
Delivery of the baby to delivery of the placenta with normal uterine contraction. The uterine contractions compress blood vessels formerly supplying the placenta, which shears away from the uterine wall.
Describe active management of the third stage?
Ecbolic injection (massive dose of oxytocin - uterine wall will contract so placenta will get loose from the wall); early clamping and ligation; controlled cord traction. Active management minimises haemorrhage.
Describe physiological management of the third stage?
Not clamping cord until pulsations cease; no traction; expulsion of placenta by maternal effort.
How do you document progress in childbirth?
Use a cartogram - essentially it can measure the baby’s heart rate.
What is slow progress of childbirth?
This is where there is:
1. <1cm/hour of dilation.
2. Prolonged labour > 12 hours.
The cause is either the three Ps.
What is the cause of slow progress in childbirth?
1. Power - Insufficient uterine action. Augmentation: oxytocin.
2. Passenger - Fetal size OR disorder of rotation (OP/OT).
3. Passage - Cephalon-Pelvic disproportion.
Describe instrumental delivery?
Can use instrumental delivery during low and mid-cavity labour - use forceps and ventouse.
1. Forceps = possibly quicker, more maternal birth canal injuries, and more neonatal facial nerve palsies.
2. Ventouse = rotation possible, however more neonatal cephalhaematomas.