Labour and Delivery Flashcards
Three phases of first stage of labour
latent, active, transition
Latent phase of stage 1 of labour
0-3cm dilated, painful contractions, may or not be continuous
active phase of stage 1
this is between 4 and 7cm dilation. This progresses at 1cm an hour with regular contractions.
Transition phase of stage 1
- this is between 7 and 10cm dilation and progresses at 1cm an hour with strong regular contractions.
Braxton Hicks contractions
These are occasional irregular contractions of the uterus. They are usually felt during T2 and T3. Women will experience temporary and irregular cramping / tightening in the abdomen. BH contractions do not indicate labour onset and do not progress or become regular.
4 signs of labour (presentation)
Show - mucus plug leaving cervix
Rupture of the membranes aka water breaking
Regular, painful contractions
Dilating cervix on examination
NICE say established first stage of labour is when (2)
Regular painful contractions
Dilation of the cervix past 4cm
Rupturing of the membranes is when
the amniotic sac ruptures
Spontaneous rupture of membranes is when
the amniotic sac ruptures spontaneously
Premature rupture of the membranes is
when the amniotic sac ruptures before the onset of labour
Preterm prelabour rupture of the membranes is when
the amniotic sac has ruptured before the onset of labour and before 37 weeks gestation
Prolonged rupture of the membranes is when
the amniotic sac ruptures more than 18 hours before delivery.
Before which week is a baby considered premature
37 weeks
Non viable babies are babies born before
23 weeks gestation (10% survival rate). If a baby is born between 23 and 24 resus is not considered if babies show no sign of life.
WHO classification of prematurity
<28 weeks is Extreme preterm
28-32 weeks is very preterm
32 -37 is moderate to late preterm
2 forms of prophylaxis for preterm labour
vaginal progesterone, cervical cerclage
Vaginal progesterone is given as prophylaxis for preterm (stopping a preterm happening) because
progesterone maintains pregnancy / prevents labour by decreasing myometrial activity and inhibiting cervical remodeling.
Who is vaginal progesterone offered to?
This is offered to women who have a cervical length of less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation.
What is Cervical cerclage
This is putting a stitch in the cervix to add support and keep it closed. It’s done under spinal / GA. The stitch is removed when the woman goes into labour or reaches term.
Who is cervical cerclage offered to?
This is offered to women who have a cervical length of less than 25m on vaginal ultrasound between 16 and 24 weeks gestation but also have previous premature birth or cervical trauma (eg colposcopy and cone biopsy)
When can a rescue cervical cerclage be offered
between 16 and 27+6 weeks gestation when there is cervical dilation with no rupture of the membranes, this prevents progression to premature delivery.
What happens in preterm labour with intact membranes
There are regular painful contractions and cervical dilation but no amniotic sac rupture.
NICE recommendations for diagnosing preterm labour with intact membrane Less than 30 weeks gestation
A clinical assessment alone is enough to offer preterm management
NICE recommendations for diagnosing preterm labour with intact membrane more than 30 weeks
A transvaginal ultrasound to assess cervical length
When it’s less than 15mm management of preterm can be offered
Cervical length over 15mm indicates preterm is unlikely
5 features of Management of preterm
Fetal monitoring
Tocolysis with nifedipine
Maternal corticosteroids can be offered before 35 weeks
IV magnesium sulfate can be offered before 34 weeks (protects babies brain)
Delayed cord clamping / cord milking
Tocolysis
Tocolysis is using medication to stop uterine contractions.
Which medication is used in tocolysis
Nifedipine is a calcium channel blocker and the medication of choice. If nifedipine is contraindicated (why) then atosiban is an oxytocin blocker that can be used.
When can Tocolysis can be used (dates)? and why?
between 24 and 33+6 weeks gestation in preterm labour to delay delivery buying time for further fetal development, administration of maternal steroids or to transfer to a more specialist unit (somewhere with an neonatal ICU). tocolysis is only used short term, e.g. for 48 hours.
absolute contraindications for tocolysis (3)
Chorioamnionitis
Foetal death or lethal abnormality
Maternal or foetal condition requiring immediate delivery
Relative contraindications for tocolysis (5)
Foetal growth restriction or distress Pre-eclampsia Placenta praevia Abruption Cervix >4cm
Tocolytics used in caution with
in diabetes and multiple pregnancy due to pulmonary oedema risk.
Why are antenatal steroids given
Giving the mother corticosteroids is done to help develop fetal lungs and to reduce the chance of respiratory distress syndrome post delivery.
When are antenatal steroids given
less than 36 weeks
Antenatal steroids regimen
two doses of IM betamethasone 24 hours apart.
Why is IV magnesium sulfate given
IV magnesium sulfate maternally helps protect the fetal brain during premature rupture delivery. It reduces risk and severity of cerebral palsy.
When is IV magnesium sulfate given?
It is given within 24 hours of delivery of preterm babies before 34 weeks gestation as a bolus followed by infusion for 24 hours/ until delivery.
3 key signs for magnesium toxicity to look out for when mg sulfate given
Reduced resp rate
Reduced BP
Absent patellar reflex’
2 tests for proteins that are high in amniotic fluid and not in vaginal fluid used to confirm preterm premature rupture
Insulin like growth factor binding protein (IGFBP-1)
Placental alpha microglobulin 1 (PAMG-1)
Management for preterm premature rupture (4 points)
Prophylactic antibiotic to prevent the development of chorioamnionitis
NICE 2019 say give 250mg erythromycin 4x daily for ten days
Or until labour is established if within 10 days
If 34+ weeks then do induction of labour
Causes of delays in labour - 3 p’s
Power (uterine contractions), passenger (foetal skull), passage (pelvic structure)
When is induction of labour offered (weeks)
between 41 and 42 weeks of gestation.
When is induction of labour offered (complications x6)
Premature rupture of membranes Fetal growth restriction Pre eclampsia Obstetric cholestasis Existing diabetes Intrauterine fetal death
When is the bishop score used?
when deciding whether labour should be induced or not.
Bishop scoring system & values
Fetal station 0-3 Cervical position 0-2 Cervical dilation 0-3 Cervical effacement 0-3 Cervical consistency 0-2
What bishop score suggests a successful induction of labour?
8+
bishop score <8 suggests
cervical ripening may be required to prepare the cervix.
bishop score > 9
labour will likely happen spontaneously
bishop score <5
indicates labour is unlikely to start without induction
5 options for inducing labour
Membrane sweep, vaginal prostaglandin E2, cervical ripening balloon, artificial rupture of the membrane, oral mifepristone plus misoprostol
4 options when induction doesn’t work initially
Further vaginal prostaglandins
Artificial rupture of the membranes and oxytocin infusion
Cervical ripening balloon
Elective c section
