Induction, Augmentation and Dystocia Flashcards
Define Induction
the initiation of contractions in the pregnant patient not in labor before spontaneous labor; from 0cm/no contractions.
Define augmentation
enhancement of contractions in the pregnant patient already in labor. Get contractions stronger, longer, and closer together.
Define cervical ripening
use of pharmacological or other means to soften, efface and/or dilate the cervix to increase likelihood of vaginal delivery when induction is indicated
True or false: the goal of cervical ripening is to begin contractions
False - to get cervix in position for labor
Typical position of cervix at onset of labour
50% effaced and 2cm dilated
Describe a ripe cervix
shortened, centred/anterior, softened and partially dilated
In general, what are the indications for induction/augmentation
Any reason that an improved outcome would occur with baby coming sooner
Examples of induction/augmentation indications
§ Post-term Pregnancy (41+ or more weeks gestation /w confirmed dates)
§ Hypertensive disorders (pre-eclampsia)
§ Diabetes mellitus
§ Significant maternal disease not responding to treatment
§ Significant, but stable antepartum bleeding
§ Chorioamnionitis: infection between layers of amniotic sac
§ Oligohydramnious
§ Suspected fetal compromise
§ Rh Isoimmunization at / or near term
§ IUGR
§ PROM (labor onset not occurring 12-24h post rupture) at or near term (esp if GBS positive)
§ Intrauterine fetal death/Intrauterine death in previous pregnancy
§ Advanced age
§ Logistical concerns r/t vicinity to hospital
What does the SOGC recommend as a requirement for induction of labor?
Obstetrical/Medical Indication
- PROM before 41 weeks
- HTN
-IUGR
What is the SOGC guideline for induction of post-mature pregnancies?
At or after 41 weeks in the absence of any other health concerns
What are the maternal risks of post-term delivery?
All related to macrosomia
- increased chance of c-section
- dystocia
- birth trauma
- PPH
- infection
What are the fetal risks for postterm delivery?
Macrosomia (large fetus), shoulder dystocia, brachial plexus injuries, low APGAR, post maturity syndrome, cephalopelvic disproportion
What occurs to the post term placenta?
As placenta ages its perfusion decrease and it is less efficient at delivering oxygen and nutrients
What occurs to postterm amniotic fluid?
volume declines after 38 weeks increasing risk for cord compression
What is there an increased risk for regarding meconium in postterm delivery?
The longer the fetus is inside, the more likely they are to pass meconium, increasing risk for aspiration
Why is G5 or higher caution for induction?
o Can be very sensitive to induction; baby come very quick
Why is vertex not fixed in pelvis caution for induction
Worried about cord prolapse r/t head in improper position
Possible dystocia
What regarding the cervix is a caution for iduction
Unfavorable/unripe
- ripening needs to occur first
Why are brow/face presentation cautions for induction?
The diameter of the presenting part through cervix is large
Why is over-distention of the uterus a caution for induction?
Muscle may be hypersensitive and be overstimulated and increase risk of PP hemorrhag
Why is a lower segment uterine scar an extreme caution for induction?
You can labour with a LS scar, but adding induction can increase
Risk of rupture
In general, what are contraindications to induction
Any contra-indication to vaginal delivery
What Bishop score is predictive of success?
7 or greater
What 6 factors does the bishop score assess?
dilatation, effacement, length, consistency, position, station
Bishop Score Dilatation 0, 1, 2
0, 1-2, 3-4
Bishop Score Effacement 0, 1, 2
0-30, 40-50, 60-70
Bishop Score Length, 0, 1, 2
> 3, 1-3, <1
Bishop Score Consistency, 0, 1, 2
Firm, medium, soft
Bishop score position 0, 1, 2
posterior, mid, anterior
Bishop score station, 0, 1, 2
-3 or above, -2, -1/0
What methods are used to prevent IOL/stimulate so IOL doesn’t have to occur?
Nipple stimulation - oxytocin release
Sex - semen has prostaglandins/pressure on cervix
Enema/Oil - increases motility
Stripping/Sweeping membranes
Prenatal hand expression
3 General Methods of IOL
- amniotomy
- mechanical dilation
- pharmacological
What is stripping/sweeping membranes?
Mechanical seperation of membranes from cervix/uterus (non-pharm induction method)
2 physiological effects of stripping membranes as induction method
- seperates membranes
- enhances prostaglandin release for ripening
3 Mechanical Dilation Methods for IOL
- foley
- CRB
- laminaria
How does laminaria induce labor?
Seaweed has massive capacity to absorb fluid and swell up, forcing cervix ope
Why would a patient undergo an amniotomy?
Augmentation or induction when a patient is committed to delivery (not going home)
Considerations for an AROM
- patient will not be going home
- need fetal/contraction monitoring
- rx for infection and cord prolapse
Besides induction/augmentation, when else would an AROM occur?
Whenever fetal access is necessary
- obtain fetal scalp blood sample for pH monitoring
- apply internal scalp electrode
What is the ideal pharmacological method for cervical ripening?
Prostaglandins
What 2 general mechanisms of actions occur regarding the pharmacological management of induction/augmentation
- cervical ripening - prostaglandin
- uterotonic - oxytocin
What is prostin?
Prostaglandin gel inserted into posterior fornix of vagina for cervical ripening
Considerations of prostin use?
Gel
Risk is less reversible, harder to remove gel if contractions are too long, strong, with no time inbetween
What is cervidil?
Prostaglandin vaginal insert into posterior fornix for slow continuous release - patient can go home and remove when contractions are occuring at correct rate
What is misoprostol/cytotec?
Prostaglandin synthetic tablet (oral/vaginal) for induction
Oral recommended so titration can occur
Besides induction, what else is misoprostol/cytotec indicated for
Anti-ulcer agent, PPH prevention
(Induction is off label use)
Prostaglandins are used for: Whereas oxytocin is used for:
Induction
Induction AND augmentation
Half life of oxytocin and benefit?
Half-Life is ≈ 1-6 minutes
Short half-life, if something isn’t occurring as desired can turn off continuous infusion and effects will be immediate
How is oxytocin for induction/augmentation administered and special considerations?
Secondary line at proximal port
§ Prime line with mixture because it takes 19.6ml to prime secondary line, running at 2ml an hour – only getting NS
True or false oxytocin is effective on cervix
False, ripening should occur first
Nursing Care for Oxytocin Induction
- continuous observation
- contractions and FHR q15
- maternal VS q15-30
What is the major thing your are assessing for during oxytocin induction?
Tachysystolic uterine activity through assessment of resting tone and FHR to assure there is no reduction in blood flow
If tachysystolic contractions occur during oxytocin administration, what would occur?
Decrease titration
What can tachysystolic uterine contractions cause?
placental abruption, fetal hypoxia, precipitous delivery, postpartum hemorrhage/uterine atony
Interventions for tachysystolic uterine contractions
- Re-position (Left lateral, side to side, knee chest)
- Reduce uterine stimulation:
- or stop oxytocin
- remove cervidil
- swab out prostin
- Continue monitor
- Administer ordered tocolytic if indicated
- Provide support and reassurance
- Consider O2 and IV bolus if indicated
Why is the risk for PPH increased following oxytocin administration?
Uterus becomes reliant on steady source of oxytocin to contract - failure to contract leading to subinvolution
What dystocias can occur regarding “powers”
- hypertonic uterine dysfunction: uterus contracts too frequently/strongly making it difficult/not allowing enough time for cervix to dilate and baby to descend
- Hypotonic uterine dysfunction: uterus not contracting strongly enough
- Precipitate labor: rapid labor
Define dystocia
difficult or obstructed or non progression labour
What dystocias can occur regarding the “passageway?”
- Pelvic contraction
- Obstructions in maternal birth canal
What dystocias can occur regarding the “passenger?”
- breech/shoulder presentation
- cord prolapse
- persistent occiput posterior position
- face/brow presentation
- macrsomia
What is labor dystocia?
Non progression in active labor
What interventions occur for labor dystocia?
Amniotomy or oxytocin
When labor dystocia occurs, what interventions increase likelihood of vaginal delivery?
Those done in ACTIVE labor
When labor dystocia occurs, what interventions increase likelihood of c-section?
when done for slow progress in latent/early labour
* Early/latent labour is SLOW
