Lecture 3: Labor Flashcards
What are the components of a cervical exam?
- Dilation: How open internal os is. 10cm or more = complete
- Effacement: length of cervix (thickness/difference between internal and external os)
- Station: Degree of descent of presenting part of fetus (cm from ischial spine, measured in 3rds)
- Consistency: More firm = not in labor
- Position: anterior, mid anterior, posterior
What is required to dx labor?
Cervical change.
Contractions without changes = braxton hicks
What is the Bishop score?
Favorability of cervix for labor, determined via cervical exam results
> 8 score = favorable
What are the 4 ways to check membrane status during labor?
- Ferning
- Nitrazine paper on fluid
- Presence of pooling/cervical leakage during valsalva
- AFI (amniotic fluid index)
When is GBS screened for and how is it treated if positive?
- Screened at 35 weeks for all women.
- PCN (erythro/clinda or vanco)
C&S determines erythro vs vanco
Common cause of neonatal sepsis
Why are IV pain meds generally avoided in labor?
Can cause nonreassuring fetal status and respiratory distress
Where is an epidural given in labor? What are the complications and contraindications?
- Placed in the L3-L4 space
- Complications: maternal hypotension, respiratory depression, or spinal HA
- Contraindications: Maternal bleeding disorder or use of LMWH within 12h, or refusal
When is spinal anesthesia primarily used?
C-section
When is a pudendal block utilized in labor?
- Operative vaginal delivery
- Extensive perineal repair post delivery
When is general anesthesia utilized for labor?
Emergent/urgent settings, as the fetus gets anesthetized too.
What bishop score correlates with a poor result in induced labor?
< 5 is generally 50% failure
However, cervical ripening can help
What drug class is used for cervical ripening and why?
PGE1 (cervidil) & PGE2 (cytotec), which cause dissoution of collagen bundles and increase water uptake.
Prostaglandin
SEs and CIs of cervidil (PGE1) & Cytotec (PGE2)
- SEs: Tachysystole, Fever, V/D, uterine rupture
- CIs: Hx of C-section, myomectomy, hysterotomy
What is pitocin?
IV equivalent of oxytocin
SEs and contraindications of pitocin?
- SEs: tachysystole, uterine rupture (rarer than PGEs), HypoN, Hypotension, amniotic fluid embolism
- CI: fetal distress, HSR
What are the mechanical methods for inducing labor?
- Balloon catheter (cook)
- Laminaria (seawood to pull out water and dilate cervix)
- Amnio hook to puncture sac (better if multipara)
Balloon catheter + pitocin = good combo
What drug is typically used to augment labor?
Pitocin
What are the two ways operative vaginal delivery is done?
- Forceps
- Vacuum
When is operative vaginal delivery indicated?
- Prolonged 2nd stage of labor
- Maternal exhaustion
- Hasten delivery to prevent fetal compromise
What are the 4 stages of labor?
- Onset of labor to complete cervical dilation
- Complete cervical dilation to expulsion of fetus
- Delivery of infant to delivery of placenta
- Delivery of placenta to 1 hour postpartum
When it comes to spontaneous labor, is primip or multip quicker?
Multipara becomes quicker once the cervix is dilated 6cm.
What phase of labor is prolonged if labor has to be induced?
Latent phase
What are the 2 phases in stage 1 of labor?
- Latent phase, 0cm to 6cm (slow)
- Active (6cm to complete)
Stage 1 lasts 6-8 hours for multips, 10-12 for primips
What are the factors that affect the active stage of labor?
- Power: uterus
- Passenger: fetus
- Pelvis: opening the fetus comes out of
3 P’s
How can uterine contraction force be measured?
IUPC (Intrauterine pressure catheter) or via external tocodynamometry
What is considered adequate labor?
- 3-5 contractions in a 10 minute period
- > 200 montevideo units in a 10 minute period
What is required to measure montevideo units?
IUPC
What two aspects of the passenger affect labor?
- Fetal size: Macrosomia
- Fetal lie: longitudinal, transverse, oblique
Ideal is butt up
What is breech position for a baby? Funic? Compound? Vertex?
- Breech: butt down, (sacrum reference)
- Funic/cord: umbilical cord
- Compound: something in front of baby
- Vertex: head down, (occiput reference
Fetal Presentation image
What is Leopold’s maneuver?
Abdominal palpation of supine mother to determine fetal variables
Does not work well if obese, polyhydraminos, or multifetal gestation
U/S is overall the best way.
If a baby does not present in vertex position, what is the most likely delivery method to pursue?
C-section
What macrosomia weight should be considered for C-section?
Fetus > 5kg or 4.5kg for diabetic mothers
What pelvic finding indicates C-section is needed?
Small pelvic outlet
Image of Pelvis shapes
What is active phase arrest of labor?
- No progression in dilation for pts > 6cm dilation with 4 hours of adequate uterine activity.
- OR 6 hours of inadequate uterine activity + pitocin augmentation
C-section needed
What is considered a prolonged 2nd stage of labor?
> 3 hours of pushing in nullip individuals or 2+ in multips.
C-section needed
What is an umbilical cord prolapse?
When the sac pops and the umbilical cord goes in front of fetal head.
What two things indicate the second stage of labor has begun?
- Increasing pelvis/rectal pressure
- Mother begins active role of pushing
What is molding? Caput?
- Molding: cranial bones gets compressed to pelvis temporarily
- Caput: localized edema on scalp due to cervix
What are the 4 degrees of a perineal laceration?
- 1st degree: injury to perineal skin and vaginal mucosa only
- 2nd degree: Injury to perineal body
- 3rd degree: Injury through external anal sphincter
- 4th degree: Injury through rectal mucosa
What is an episiotomy?
Surgical incision of female perineum, used to increase diameter of the soft tissue outlet.
ACOG only supports restricted use of this.
Mediolateral often more painful due to the muscles being cut
What is shoulder dystocia?
Difficulty in delivering anterior shoulder through pubic symphysis.
How is shoulder dystocia diagnosed?
Routine delivery fails to deliver anterior shoulder
Turtled sign may suggest presence.
What are the 3 signs of the 3rd stage of labor?
- Lengthening of umbilical cord
- Gush of blood
- Fundus becomes globular and more anteverted against abdominal hand
What needs to be monitored primarily during the 4th stage of labor?
- BP
- Uterine blood loss
- Pulse
High risk for postpartum hemorrhage
Dx of postpartum hemorrhage
- > 500cc blood loss in vaginal delivery
- > 1000cc blood loss in C-section
What are the 7 distinct cardinal movements of labor?
- Engagement
- Descent
- Flexion
- Internal rotation
- Extension
- External rotation/restitution
- Expulsion
EDFIEEE
What is engagement?
Passage of widest diameter fetal part below plane of pelvic inlet
Head is engaged if leading edge is at level of ischial spines.
Define descent
Downward passage of presenting part through bony pelvis
Define flexion in labor
- Passive movement as head descends , allowing head to squish through
- Smallest diameter = subocciptobregmatic diameter
Define internal rotation of the fetus
- Fetal head rotates from occiput transverse to occiput anterior or posterior
Define extension of the fetus
- Fetus has descended to level of the fetal introitus
- Occiput past symphysis will start to change birth canal angle back upwards
Occiput is the bottom back of the skull
Define external rotation/restitution of the fetus
- Head rotates back to original position as fetus head is delivered
- Head aligns with torso automatically
- Head should return to normal
Define expulsion of the fetus
- Delivery
- Downward traction to release shoulder
What is normal fetal HR? (FHR)
110-160 BPM
What two maternal conditions commonly can result in fetal bradycardia?
- Congenital heart block 2/2 SLE
- Maternal hypotension
Primarily concerned with fetal bradycardia over tachycardia
What are the two MCC of fetal tachycardia?
- Infection
- Terbutaline (bronchodilator)
What is considered abnormal variation in FHR?
- Absent = worrisome
- > 25 BPM change = worrisome
Measured over a 10 minute window
1-5 = sleeping/inactive
5-25 = normal
What are accelerations?
- > 32 weeks = 15 BPM for 15s
- < 32 weeks = 10 BPM for 10s
15 for 15 or 10 for 10
What are early decelerations?
- Occurring at the same time as a contraction
- Vasovagal response to head compression
- No intervention needed
What are late decelerations?
- Beginning at peak of contraction and returns baseline at conclusion
- Result of uteroplacental insufficiency (O2)
- Requires positioning, o2, stopping pitocin, and a fluid bolus.
- Consider C-section
Baby HR will drop during contract since it is not getting enough o2.
What are variable decelerations?
- Occur anytime
- Result of cord compression
- Consider intervention via amnioinfusion (NS into sac via IUPC)
V-shaped HR drops
Deeper and longer duration = more concerning
What is a sinusoidal waveform and what does it suggest?
Fetal anemia
What are the categories for FHR tracings?
- Cat 1: Normal FHR + moderate FR variability + no late or variable decels + accels can be present (good!)
- Cat 2: Anything not Cat 1 or 3
- Cat 3: Absent FHR variability with either recurrent late decels, recurrent variable decels, or brady cardia. Sinusoidal waveform
What is a contraction stress test?
Evaluate fetal response via pitocin to achieve 3 contractions in 10 minutes.
Used to evaluate fetal status prior to induction of labor
Interpretation of a contraction stress test
- Positive: C-section needed due to late decels occurring in more than 1/2 of contractions.
- Equivocal: wait and see, nonpersistent late decels
- Negative: Good to go!
