Labour and birth Flashcards
What causes the onset of labour?
Mechanical (e.g. preterm labour commonly seen when uterus is overstretched such as in multiple pregnancies) Inflammatory markers (e.g. cytokines and prostagladins) - released if cervix is digitally stretched
What characterises the 1st stage of labour according to NICE guidelines?
Regular, painful contractions
AND
Progressive cervical dilatation from 4cm
Why should women not be examined whilst lying flat during an obstetric abdominal exam?
Risk of postural supine hypotensive syndrome
What should be included in an obstetric examination?
Observation
Inspection
Palpation
Auscultation
What should you be looking for in an inspection during an obstetric examination?
Abdominal mass Striae Gravidarum (stretch marks) Surgical scars
When should palpation be included in an obstetrics examination?
From 36 weeks gestation
What does palpation determine in an obstetrics examination?
Position of foetus
Size of uterus (fundal height)
Where would you expect the fundal height of the uterus to be at 12, 20 and 36 weeks?
12 weeks = pubic symphysis (not palpable)
20 weeks = umbilicus
36 weeks = xiphisternum
[Then begins to drop down as the foetal height engages into the maternal pelvis]
What is “foetal lie”?
Relationship between the long axis of the foetus and the long axis of the uterus - longitudinal when long axis of foetus is aligned to mother
[Can also be transverse when long axis of foetus is perpendicular to mother or oblique when long axis of foetus is 90-180 degrees to mother]
What is foetal presentation?
Part of the foetus that presents to maternal pelvis
Cephalic = head
Breech = feet/legs/ hips
Transverse/ oblique = shoulder
When is the foetal head said to be engaged?
When widest diameter of head has passed through the pelvic brim
When 2 or fewer fifths are palpable (between head and pubic symphysis)
When might an obstetric pelvic examination be indicated?
Assessment of labour
Assessment of membrane rupture
Per vaginal bleeding
What should an obstetric pelvic examination include?
External examination of vulva
Internal examination of vagina and cervix (e.g. use of speculum)
What is cervical effacement?
Gradual thinning, shortening and drawing up of the cervix (measured in % from 0 to 100)
What is cervical dilation?
Gradual opening of the cervix (measured from 0-10cm)
What does station refer to during labour?
A measurement between the presenting part of baby (e.g. top of head if cephalic presentation) and an imaginary line drawn between the ischial spines of the maternal pelvis
What is a Bishop score?
System used to evaluate the favourability of the cervix for birth - the higher the score, the more favourable (each measure can score between 0 and 2)
Measures include: cervical dilatation (cm), length of cervix (cm), station of presenting part (cm), consistency and position
How is progression in labour is assessed?
Uterine contractions
Dilatation of cervix
Descent of presenting part
What is used to chart observations during labour?
Partogram
What are the expected rates of cervical dilatation in nulliparous and multiparous women?
Nulliparous = 0.5-1cm/ hr Multiparous = 1-2cm/ hr
What would indicate slow progression in labour?
Lack of cervical dilatation
Failure of descent of presenting part
What are the 3 stages of labour?
Stage 1 = onset of regular contractions with associated cervical dilatation to full dilatation of cervix (10cm)
Stage 2 = from full dilatation of cervix to birth of baby
Stage 3 = birth of baby to delivery of placenta and membranes (and control of associated bleeding)
What are the 3 P’s of labour and birth?
Power (of contractions)
Passage (birth canal)
Passenger (size, positioning, coping of baby)
[All interact towards a successful outcome]
What does the foetus do during the first stage of labour to aid delivery?
Flexion of head as cervix is dilating
How does the foetus move during the second stage of labour to aid delivery?
- Internal rotation of head as it reaches the pelvic floor to bring the occiput into the anterior position
- Extension of the foetal head as it is delivered passing under the pubic symphysis
- External rotation of the head allowing delivery of the shoulders
What is induction of labour?
Artificial initiation of uterine contractions prior to spontaneous onset resulting in delivery of baby
How can induced labour impact mothers?
Often less efficient and more painful than spontaneous onset of labour - epidural analgesia and assisted delivery more likely to be required
What are the maternal indications for induction of labour?
Severe pre-eclampsia
Recurrent antepartum haemorrhage
Pre-existing conditions (e.g. diabetes)
What are the foetal indications for induction of labour?
Prolonged pregnancy (most commonly) Intrauterine growth restriction (IUGR) Rhesus disease
What is classed as a ‘favourable’ cervix?
Soft, beginning to dilate and efface (thinning)
What are the main methods of labour induction?
Prostaglandin-Dinoprostone E2 (given locally as vaginal gel, tablet or pessary) - “ripens” cervix
Amniotomy (causes local release of endogenous prostaglandins)
Oxytocin (given IV)
What are the foetal indications for operative intervention in labour?
Foetal distress
Breech
Severe IUGR
Twins
What are the maternal indications for operative intervention in labour?
HIV
Raised ICP
Pre-eclampsia (or eclampsia)
What are the 2 main types of foetal monitoring in labour?
Intermittent auscultation
Continuous cardiotocography monitoring
[In a healthy woman with uncomplicated pregnancy, intermittent auscultation should be used]
What is meconium?
The first stool passed by baby - blackish green colour
What are the complications of meconium aspiration syndrome?
Severe respiratory distress - can cause chemical pneumonitis
What is the difference between physiological and active third stage of labour?
Physiological = no oxytocic drugs given - placenta passes passively and cord is not cut until it stops pulsating Active = use of oxytocic drug
What is delayed cord clamping and its benefits?
Cord not cut for 1-3 mins - can improve iron status, especially in premature babies
