Lecture 7.1 - At Risk Birth (Part 1) Flashcards
What is considered absent, minimal, moderate, and marked variability in FHR?
Absent - 0-3 bpm
Minimal - 4-5 bpm
Mod - 6-25 (normal)
Marked - > 25
What is the baseline FHR?
Approximate mean FHR rounded to an increment of 5 in a 10-minute tracing
–> Excludes accelerations, decels, and periods of marked variability
–> Must be present for at least 2 minutes in any 10 minute segment
What is considered fetal tachycardia? What length of time for fetal tachycardia is considered atypical or abnormal?
Baseline > 160 bpm for more than 10 minutes
Atypical: 30-80 minutes
Abnormal: 80+
Fetal tachycardia is a warning sign for what? What might it indicate?
Warning sign of fetal hypoxemia
May indicate fetal anemia
May indicate maternal fever, infection, medications or drug use
What is considered fetal bradycardia? What bradycardia is considered atypical or abnormal?
Baseline < 110 for 10+ minutes
Atypical: 100-110 bpm
Abnormal: < 100 bpm
Fetal bradycardia can indicate what?
Cardiac Problem
Viral infections
Maternal hypoglycemia
Maternal hypothermia
What is an acceleration?
Abrupt increase (<30 second) increase in FHR (15 bpm x 15 seconds) with a return to baseline in < 2 minutes.
What is considered a prolonged acceleration?
Lasting 2-10 minutes.
How are decelerations described?
Their visual onset to end of the contraction and the nature of their descent
What is an early deceleration?
Gradual decrease and return to baseline that correspond to the beginning, peak, and end of a contraction
–> Due to transient compression of fetal head
What is a late deceleration?
Gradual descent. Begins after the contraction has started and the lowest point of the deceleration occurs after the peak of the contraction. Usually does not return to baseline until after the contraction is over.
–> Persistent and repetitive late decels can be ominous
What might late decelerations indicate?
Uteroplacental insufficiency
What are variable decelerations? What might they indicate?
Abrupt in beginning and end (>15 bpm x > 15 sec)
–> Result of cord compression, usually do not have clinical significance
What is considered a prolonged deceleration?
lasting 2-10 minutes
When would a prolonged deceleration be an expected finding?
Following epidural
What is the initial intervention when there is a concerning FHR tracing?
Reposition the patient - or check maternal pulse for brady
What interventions are performed for fetal tachycardia
Reposition
Check maternal pulse + BP
Rule out fever, dehydration, drug effects, prematurity
Consider correcting maternal hypovolemia
What interventions will be performed for fetal bradycardia?
Check maternal pulse + BP
Reposition
Consider vaginal exam to rule out prolapse
Consider correcting maternal hypovolemia
What interventions are performed for late decelerations?
Reposition
Check maternal VS
If repetitive: Intrauterine resuscitation
How can we intervene for variable decelerations?
Usually correctable with repositioning
–> If complicated, assess for cord prolapse
Intrauterine resuscitation
What should we expect if abnormal tracing persist and are non-correctable?
Consider jailbreaking baby
What is involved in intrauterine resuscitation?
Stop/decrease oxytocin
Change position (start with Left Lateral)
Check maternal VS and differentiate maternal and fetal HR
Notify physician or midwife
In the second (pushing stage), what can be done as part of intrauterine resuscitation?
Modify breathing + pushing techniques
Consider cord prolapse
Administer 8-10L O2 by mask if hypoxemia suspected
Improve hydration with IV bolus if necessary
What is considered pre-term birth?
20-37 weeks
What is considered a late preterm birth?
34-37 weeks GA
–> Surfactant production is adequate
What is considered a low birth weight?
< 2500g
–> Related to any combination of factors that result in IUGR
Do most spontaneous preterm births have risk factors?
Not always predictable (1/2 of preterm births had no identified risk factors)
What percent of preterm births are indicated?
1/4
What are risk factors for spontaneous preterm birth?
Complex etiology
Family Hx
Multiple gestation
Bleeding of uncertain origin
Maternal genital tract infection
Low Pre-pregnancy weight
Low SES
Lack of access to prenatal care
What is fetal fibronectin?
A glycoprotein that adheres the chorionic membrane to the uterine decidual
When is it normal for fetal fibronectin to be found of vaginal secretions?
Up to 22 weeks and after 34 weeks.
–> Only seen between 24-34 weeks unless there is cervical dilation or effacement
What can a fetal fibronectin test predict?
Most accurate at predicting who will not give birth in the next 14 days.
–> False positives make it better at ruling out risk of preterm birth than at predicting who is going into labour soon.
How is cervical length determined?
Transvaginal ultrasound
What cervical length indicated a lowered risk of preterm birth?
> 30 mm
How can we prevent preterm birth and labour?
Main strategies are to increase preconception and prenatal care + access to the social determinants of health
All women should we aware of the signs and symptoms of preterm labour. What are they?
Uterine activity - differentiate Braxton Hicks
Discomfort - cramping, back pain
Vaginal discharge
If preterm labour symptoms begin what should patients consider doing?
Empty bladder
Drink 2-3 glasses of water
Lie down on your side for an hour and palpate for contractions
If symptoms stop, resume light activity but not what you were doing when symptoms began
If they continue or return, call HCP or go to the hospital
What are signs of preterm labour indicate that a person should go to the hospital?
Contractions q10 for 1+ hours
Vaginal bleeding
Fluid leaking
The goal of tocolytics in Canada is not to stop labour. What are their purpose?
To slow its progression - to allow for glucocorticoid administration or transfer to another unit
What is the diagnostic criteria for preterm labour?
GA 20-36 weeks
–> Regular uterine activity, change in cervical dilation/effacement or both
Initial presentation with regular contractions and cervical dilation of at least 2 cm
What activity restriction is recommended to prevent preterm labour?
Modified activity that is individualized, restriction of sexual activity
–> not bedrest (never good)
What is a major consideration when deciding whether to hospitalize a person at risk of preterm labour?
Distance from hospital
What are some contraindications to tocolysis?
If there is a condition that can harm the person or fetus, we want to end the pregnancy ASAP.
What medications are used off label as tocolytics in Canada?
Nifedipine (CCI)
Indomethacin (NSAID)
MgSO4 - inhibits uterine activity
What is the traditional approach to preventing PTB?
Bedrest, IV hydration
–> Unknown effectiveness and potential harm
Which pregnant people should receive antenatal corticosteroids? When should they receive it?
All at 24-34 weeks GA at risk of PTB in next week
–> 2 doses, 24 hours apart
There is strong evidence that a single course of antenatal corticosteroids can decrease the incidence of which complications?
RDS, IVH, NEC, death
MgSO4 can slow the labour, but this is not the main purpose of administering it. What is the main purpose? When is it indicated?
Neural protection - reduce risk of CP
Indicated when birth is imminent in next 24 hours at 24-33 weeks.
What dosage of MgSO4 is given to reduce infant morbidity/mortality?
4 gram loading dose over 30 minutes
–> Sometimes with a gram/hour maintenance infusion until birth for a maximum of 24 hours
What is premature rupture of membranes?
Spontaneous ROM before the onset of labour at any GA
Labour is induced due to risk of infection how long after ROM?
24 hour
pPROM accounts for what percent of preterm births?
33% of preterm births
What are risk factors for pPROM?
Hx of pPROM or cervical injury
STI, UTI, bleeding, uterine overdistention, trauma, PTL in current pregnancy
Short cervical length in 2nd trimester
What pre-existing maternal factors can be risk factors for pPROM?
Pulmonary disease, connective tissue disorders, low SES or BMI, nutritional deficiencies, cigarette smoking.
What are maternal complications following pPROM?
Chorioamnionitis leading to Endometritis/sepsis
Placental abruption
Complications in birth
–> Retained placenta, hemorrhage
What are fetal complications for pPROM?
Related to infection/prematurity
Placental abruption
Hypoxia d/t cord prolapse or compression
How is pPROM diagnosed?
Patient history and sterile speculum exam for visualization
Also consider Nitrazine and Ferning test
What is a Nitrazine Test? What can cause false positives?
Testing pH of fluid
–> >6.0-6.5 will turn paper blue
False positives can be caused by blood, semen, vaginal infection
What is a Ferning test?
Microscopic examination of vaginal fluid
–> Look for fern-like pattern.
When is expectant management used for pPROM?
If no contraindications, expectant management for all pts < 37 weeks
Expectant contraindicated in:
–> Active labour
–> Evidence of infection
–> Placental abruption
–> Cord prolapse
–> Abnormal fetal health serveillance
How can cord prolapse be managed?
Positioning or physical support of presenting part through vagina
What is expectant management for pPROM?
Hospitalization in facility with NICU
If 24-34+6 weeks - corticosteroids + short term tocolytics to allow for administration or transfer
Monitor for signs of infection + Prophylactic antibiotics (Amp, Erythromycin)
MgSO4 for neuroprotection
If there is no infection or complications, there is no advantage to inducing labour early
What teaching is necessary for someone with pPROM?
AF production continues
S&S of infection
Daily FA counts
Peri-hygiene
Consult with neonatologist
Psychological support
How is chorioamnionitis managed?
Broad spectrum IV antibiotics at birth
What is the difference in management of PROM vs pPROM?
With PROM we want delivery within 12-24 hours
With pPROM we want expectant management to balance hazards of prematurity and risk of infection
What is considered a post-term pregnancy?
Beyond 42 weeks GA
What are maternal risks for post-term prenancy?
Longer pregnancy - large impact on uterus’s ability to contract following delivery leading to PPH, dystocia, chorioamnionitis
Complications related to delivering large fetus - severe perineal injuries, c/s
What are some risks for the fetus with post-term pregnancy?
Higher risk of meconium aspiration, cord compression
Associated with oligohydramnios, macrosomia or small for gestational age, cord compression.
When is someone offered an induction if they do not go into spontaneous labour?
After 41+3 days.
–> Monitoring much more closely from this point onward. Will use EFM during labour.
What are the three main methods of labour induction?
Cervical ripening
Amniotomy
Oxytocin
Induced labour carries what risks?
Increased rate of c-section + NB morbidity + Cost
What is a Bishop score?
An assessment of inducibility on a 13-point scale
Assessed dilation, effacement, station, cervical consistency and position
Labour induction is usually successfully with what Bishop score?
7 or more.
Prior to induction, most people need what first step?
Cervical Ripening to soften cervix
What is membrane sweeping?
Vaginal exam that involves disconnecting the membranes from the cervix - results in release of prostaglandins and can soften cervix
What are alternative methods of cervical ripening?
Walking & sex
What is the most commonly used mechanical dilator?
Foley cath
What synthetic prostaglandins are used for cervical ripening?
PGE1
–> Misoprostol tablets
PGE2
–> Cervidil insert of Prepidil gel (both dinoprostone)
Labour usually begins how soon after AROM? When do we start worrying about infection?
within 12 hours labour begins
–> Assess for infection q2 hours
When is AROM contraindicated?
With STIS and use caution with HIV
When the presenting part is not engaged and applied to the cervix
How does synthetic oxytocin differ from endogenous oxytocin?
Synthetic does not cross BBB - Does not decrease sensitivity to pain in the way endogenous oxytocin does.
What monitoring is necessary when administering oxytocin?
EFM - monitor contraction pattern and fetal tolerance
What is dystocia?
Abnormally slow progression of labour
What is considered labour dystocia in the first active stage of labour?
Less than 0.5 cm/hour of cervical dilation over 4 hours
OR
No cervical dilation change over two hours
What are some problems with the powers that can cause labour dystocia?
Hypertonic ctx
Hypotonic ctx
Alteration to 2° (bearing down) powers)
What is considered labour dystocia during the second stage of labour?
Greater than 1 hour of active pushing with no descent on the presenting part
What problems with the passage can cause labour dystocia?
Pelvic / soft tissue dystocia
What problems with the passenger can result in dystocia?
Anomalies
CPD
Malposition (ROP or LOP)
Malpresentation (Breech, shoulder)
Macrosomia
Multifetal pregnancies
What is the nursing role following an external cephalic version?
EFM for 1 hour
Observe for bleeding
Prevent isoimmunization for Rh negs
How is a external cephalic version monitored during the procedure?
NST + US
Nurses monitor EFM, VS, and provide comfort care
What are some contraindication to attempting breech delivery?
Cord compression
fetal growth restriction
or macrosomia (Outside of 2800-4000g range)
Footling
inadequate pelvic size
Fetal anomaly
Hyperextended fetal head.
What are the different classifications of operative vaginal births based on height of the presenting part?
Outlet - visible scalp
Low - lower than 2+ station
Mid - fetus above 2+ station
High - Not engaged*
*a high operative vaginal delivery is not recommended because rates of complications are very high
What are some indications for a forceps-assisted birth?
Need to shorten a prolonged 2nd stage of labour d/t abnormal FHR, abnormal presentation, or maternal exhaustion
What are the criteria for operative vaginal births?
Cervix must be fully dilated
Bladder empty
Presenting part engaged, Membranes ruptures
Adequate pelvic size
Do operative vaginal births increase the instances of tears?
Yes, increased risk of 3rd and fourth degree perineal tears
What are the advantages are using vacuum assisted birth over forceps?
Easier to use, less anesthesia
After what age can a vacuum assisted birth be attempted?
At least 34 weeks GA to prevent neural damage to fetus.
What are the nursing considerations for operative vaginal births?
Empty bladder
Prepare for neonatal resuscitation
Prepare for anesthesia or analgesia as needed
Prepare for possible emergency c/s
What are some indications for use of tocolytics?
Slow of delay birth when…
–> There is a diagnosis of preterm labour with fetal weight < 1500g and/or immature fetal lungs
Allows time to transfer or for glucocorticoid administration
What position must the fetus be in for a vacuum assisted birth?
Vertex
