Lecture 12: Normal Labor and Delivery Flashcards
On obstetric exam what is fetal lie?
- Reference is maternal spine to fetus spine
- Determines if infant is longitudinal, transverse, or oblique
On obstetric exam what is fetal presentation?
- Presenting part of the pelvis
- Vertex, breech, transverse, or compound (vertex w/ hand)
Which maneuvers are used to determine the fetal lie?
Leopold Maneuvers
On obstetric exam what are the 5 parts of the cervical exam?
- Dilation checked at level of internal os
- Effacement: thinning of the cervix
- Station: degree of descent of presenting part of fetus
- Position and Consistency used to calculate Bishop score
When the bony portion of the fetal head reaches what level is it considered “zero” station?
Level of the ischial spines
What are the 4 stages of labor?
- First = onset of true labor to complete cervical dilation (latent and active)
- Second = complete cervical dilation to delivery
- Third = delivery of infant to delivery of placenta
- Fourth = delivery of placenta to stabilization of patient
What is the latent vs. active phase of the first stage of labor?
- Latent (early labor): period between onset of labor and is characterized by slow cervical dilation
- Active: faster rate of dilation and usually begins when cervix is dilated to 6cm; admit for labor at this stage in term gestations
What is normal rate of cervical dilation (cm/hr) in primiparas and multiparas?
- Primiparas = 1.2 cm per hr
- Multiparas = 1.5 cm per hr
How is maternal position managed during first stage of labor and can they ambulate?
- Patient may ambulate if: head is engaged and reassuring monitoring is noted
- If lying in bed, encouraged left lateral recumbent position
Which labs taken during first stage of labor and how often do you monitor vitals?
- Labs = CBC and type and screen
- Maternal monitoring = obtain vitals q 1-2 hours while in labor
How often should fetus be monitored externally if pregnancy is uncomplicated vs. complicated in the active phase of first stage and in second stage?
- Uncomplicated = q30 minutes (active phase) and q15 (second stage)
- Complicated = q15 minutes (active phase) and q5 minutes (second stage)
How is uterine activity monitored during first stage?
- External tocodyamometer
- Internal pressure catheter (IUPC) allows to assess the strength of contractions and is helpful w/ oxytocin augmentation
How often during active stage of first phase of labor do you do a vaginal/cervical exam and what is recorded?
- Perform cervical check q 2 hrs
- Record dilation, effacement, station
What are the benefit vs. risks of performing an amniotomy (AROM) during first stage of labor?
- Benefits: augment labor, allows assessment of meconium status
- Risks: cord prolapse, prolonged ruptured is assoc. w/ chorioamnionitis
What are the 7 cardinal movements of labor in order (mnemonic)?
- Engagement: presenting part at “zero” station
- Descent
- Flexion: baby’s chin to chest
- Internal Rotation: fetal head rotates so OA or OP
- Extension: station is +5; head born by rapid extension
- ER: head returns to original position in alignment w/ back and shoulders
- Expulsion: anterior shoulder delivers, followed by posterior
Which maternal position should be avoided during second stage of labor and what is the most common position to have mother in?
- Avoid the supine position
- Dorsal lithotomy position is most common
What are 2 indications for performing an episiotomy; what is the most common type?
- Likelihood of spontaneous laceration seems high
- To expedite delivery by enlarging the vaginal outlet (if baby is too big)
- Midline episiotomy is most common
What is a 1st vs. 2nd vs. 3rd vs. 4th degree perineal laceration?
- 1st: superficial laceration involving vaginal mucosa and/or perineal skin
- 2nd: laceration extending into muscles of the perineal body but does not involve anal sphincter
- 3rd: laceration extends into or completely through the anal sphincter but not into the rectal mucosa
- 4th: involves the rectal mucosa
What are 4 classic signs of placental separation which indicate that you should begin to apply pressure on the cord?
- Gush of blood from vagina
- Lengthening of the umbilical cord
- Fundus of uterus rises up
- A change in shape of the uterine fundus from discoid –> globular
What is the most common cause of postpartum hemorrhage during the fourth stage?
Uterine atony
What is induction of labor vs. augmentation of labor?
- Induction is the process by which labor is induced by artificial means
- Augmentation is the artificial stimulation of labor which has already begun
What are 5 contraindications to induction of labor?
- Unstable fetal presentation
- Acute fetal distress
- Placental previa or vasa previa
- Previous classical C-section or transfundal uterine surgery (i.e., myomectomy)
- Any contraindication to vaginal delivery (i.e., HIV w/ high viral load, active genital HSV outbreaks, etc.)
Which Bishop score is considered unfavorable and what is considered favorable?
- <6 is unfavorable
- >8 the probability of vaginal delivery after labor induction is similar to that of spontaneous labor
What is a downside of using Misoprostol vs. Dinoprostone for cervical ripening?
- Misoprostol cannot be readily removed if concerns arise
- Dinoprostone is a vaginal insert that can be removed
What is the only FDA approved drug for induction and augmentation?
Pitocin (synthetic oxytocin) given IV
What are some of the AE’s associated with Pitocin administration?
- Uterine tachysystole = most common AE
- Antidiuretic effect due to similar structure as ADH
- Uterine muscle fatigue (nonresponsiveness) will prolonged use
What effect may regional anesthesia have on uterine blood flow; what can be done to mitigate this risk?
- May ↓ uterine blood flow if hypotension occurs and is not promptly tx
- Adequate hydraton (IV bolus) 30-60 min prior may mitigate the risk for hypotension
What is an epidural?
- A catheter is placed in the epidural space which allow for continous infusion of anesthetic agents
- Large bore needle is used to locate epidural space btw L2-L5 interspaces
When is parenteral administration of pain meds more effective during labor; what are some downsides?
- More effective in early first stage of labor when pain is more visceral and less intense
- Have very little efficacy for relief of labor pain (more sedative); also opioids CAN cross the placenta
What are 5 contraindications for doing regional anesthesia during labor?
- Maternal coagulopathy
- Heparin use within 12 hrs
- Untreated maternal infection
- ↑ ICP due to mass lesion
- Skin infection over site of needle placement
What is the most common induction agent used for general anesthesia in emergent cases w/ need for rapid delivery arise or regional anesthesia has failed?
Propofol
What is the anesthesia related risk of maternal mortality with general anesthesia vs. regional anesthesia?
General anesthesia carries a 16-fold ↑ anesthesia related risk
