Clin: Normal Labor and Delivery - Moulton Flashcards
what shape is the anterior fontanelle?
diamond shaped, 2x3 cm
what shape is posterior fontanelle?
Y or triangular shape
suboccipitobregmatic
head well flexed
occipitofrontal
head deflexed
- occiput posterior position
supraoccipitomental
brow presentation
- is the longest anterior-posterior diameter of the head
submentobregmatic
face presentation
what is the average circumference of a term fetal head measured in the occipitofrontal plane?
34.5cm
classic female type of pelvis (50% of females)
- round at the inlet
- wide transverse diameter only slightly greater than AP diameter
- wide suprapubic arch
- head generally rotates into occiput anterior position = good prognosis for delivery
gynecoid
classic male type of pelvis (30% of females)
- widest transverse diameter closer to sacrum
- prominent ischial spines
- narrow pubic arch
- fetal head is forced to be in occiput posterior position
- amount of space is restricted and arrest of descent of common = poor prognosis for delivery
android
resembles an ape pelvis (20% of females)
- much larger anteroposterior then transverse diameter
- creates a long narrow oval shape
- narrow pubic arch
- fetal head engages only in AP diameter
- usually OP position = good prognosis for delivery
anthropoid
reference is maternal spine to fetus spine
- determines if infant is longitudinal, transverse, or oblique
fetal lie
presenting part to the pelvis
- vertex, breech, transverse, or compound (vertex with hand)
fetal presentation
- palpate the fundus
- palpate for sping and fetal small parts
- palpate what is presenting in the pelvis with suprapubic palpation
4 palpate for cephalic prominence (can feel chin or occipital protuberance if head is not deep in pelvis)
leopold maneuvers
thinning of the cervix occurs and is reported as % change in length
- normal length is 3-5 cm
- range is thick - 100%
effacement
degree of descent of the presenting part of the fetus
- measured in cm from presenting part to ischial spines
- when the bony portion of the head reaches the level of the ischial spines = 0
- range -5 to +5
station
onset of true labor to complete cervical dilation
- latent and active phases
FIRST stage
complete cervical dilation to delivery of infant
SECOND stage
delivery of infant to delivery of placenta
THIRD stage
delivery of placenta to stabilization of patient
FOURTH
period between onset of labor and is characterized by slow cervical dilation
latent (early) labor
faster rate of dilation and usually begins when cervix is dilated to 6cm
- admit for labor at this stage
active labor
what is the duration of first stage for primips?
6-18 hours
what is the duration of first stage for multips?
2-10 hours
what is the bare minimum rate of cervical dilation for primips?
1.2 cm per hour
what is the bar minimum rate of cervical dilation for multips?
1.5 cm per hour
what med is used AUGMENT labor?
oxytocin
what labs should be drawn during the first stage of labor?
CBC and T&S (type and screen)
how often should you be monitoring if uncomplicated pregnancy?
- q 30 minutes in active phase of first stage of labor
- q 15 minutes in second stage of labor
how often should you be monitoring if complicated pregnancy?
- q 15 minutes in active phase (following a contraction)
- q 5 minutes during second stage
what allows you to assess the strength of the contractions and is helpful with oxytocin (Pitocin) augmentation?
internal pressure catheter (IUPC)
how often should a vaginal exam be done during active phase of labor?
cervical check q 2 hrs
- record dilation/effacement/station
what are the benefits and risks of anmiotomy (AROM)?
- benefits: augment labor, allows assessment of meconium status
- risks: cord prolapse, prolonged rupture associated with chorioamnionitis
what is the reference point for fetal POSITION?
the occiput
- occiput posterior = occiput is facing backwards
- left occiput transverse = occiput is facing toward the moms left hip (face is looking right)
what are signs of second stage of labor?
mother usually has increase in bloody show and desire to bear down with each contraction
how long is the average primip second stage without epidural?
2 hours
how long is the average primip second stage WITH epidural?
3 hours
how long is the average mulip second stage without epidural?
1 hour
how long is the average multip second stage WITH epidural?
2 hours
what are the 7 cardinal movements of labor?
- engagement
- descent
- flexion
- internal roation
- extension
- external rotation
- expulsion
defined as presenting part at “zero” station
engagement
brought about by the force of uterine contractions and maternal valsalva efforts
descent
OA - baby’s chin to chest thus changing the presenting part from occipitofrontal to smaller suboccipitobregmatic
flexion
occurs usually at the ischial spines
- fetal head enters pelvis in transverse diameter, rotates so the occiput turns anteriorly or posteriorly toward the pubic symphysis
internal rotation
crowning occurs when the largest diameter of the fetal head is encircled by the vaginal introitus
- station is +5
- head is born by rapid extension
extension
the delivered head now returns to its original position at the time of engagement to align itself with the fetal back and shoulders
external roatation
the anterior shoulder then delivers under the pubic symphysis, followed by the posteriors shoulder and the remainder of the body
expulsion
what position should the mother avoid during second state?
supine
when should fetal monitoring occur during second stage?
continuously
- monitor q 15 minutes in second stage with NO risk
- monitor q 5 minutes WITH risk factors
how do you assess for nuchal cord?
index finger
- if loose: can manually reduce over infants head
- if tight: need to clamp x2 and cut
what is the most common episiotomy performed?
midline
- greater risk of extension into third or fourth degree
- less postpartum pain
what are the risks or mediolateral episiotomy?
- greater blood loss
- more difficult to repair
- more postpartum pain
- increase risk of dyspareunia (painful intercourse)
finger to the right hand are used to extend the head while counter pressure is applied to the occiput by the left hand to allow for a more controlled delivery
modified Ritgen maneuver
superficial laceration involving vaginal mucosa and/or perineal skin
first degree
laceration extending into muscles of the perineal body but does not involve the anal sphincter
second degree
laceration extends into or completely through the anal sphincter but not into rectal mucosal
third degree
involves the rectal mucosa
fourth degree
what is diagnosed if the placenta is has not been delivered within 30 minutes?
retained placenta
- usually occurs between 2-10 minutes
- gush of blood from the vagina
- lengthening of the umbilical cord
- fundus of the uterus rises up
- a change in shape of the uterine fundus from discoid to globular
classic signs of placental separation
that should you actively do in the third stage of labor
apply counter pressure between the symphysis and fundus
- do NOT pull on cord until classic signs are noted
- inappropriate pulling may result in uterine inversion :((
what is the most common cause of postpartum hemorrhage?
uterine atony during the fourth stage
- retained placenta or un-repaired lacerations can also cause hemorrhage
what is the goal of cervical ripening?
facilitate the process of cervical softening, thinning and dilating in hopes to reduce the rate of failed induction
process by which labor is started by artificial means
induction
artificial stimulation of labor that has already begun
augmentation
- abruptio placentae
- chlorioamnionitis
- fetal demise
- preeclampsia, eclampsia
- PROM
- post-term pregnancy
indications for induction
- unstable fetal presentation
- acute fetal distress
- placenta previa or vasa previa
- previous classical cesarean or transfundal uterine surgery
contraindications to induction
what is considered an unfavorable bishop score?
<6
what is considered a favorable bishop score?
> 8, probability of vaginal delivery after labor induction is similar to that of spontaneous labor
what score does cervical dilation get on bishop score?
closed = 0 1-2 = 1 3-4 = 2 >5cm = 3
what score does cervical effacement get on bishop score?
0-30 = 1 40-50 = 1 60-70 = 2 >80 = 3
what score does station get on bishop score?
-3 = 0
-2 = 1
-1-0 = 2
>+1 = 3
what score does cervical consistency get on bishop score?
firm = 0 med = 1 soft = 2
what score does cervical position get on bishop score?
posterior = 0 midline = 1 anterior = 2
- cervidil (PGE2, vaginal insert, contraind in pt w/ previous c-section)
- cytotec (PGE1, orally or vaginally, cannot be readily removed, contraind in pt w/ previous c-section)
- foley bulb catheter (inflate 30-80cc)
- laminara japonicum (dilation occurs by swelling of the laminara rods)
cervical ripening agents, ONLY used to augment, never to induce labor
synthetic oxytocin
- IV adiministered, diluted in normal saline
- only FDA approved drugs for induction and augmentation
- uterine response ensues 3-5 minutes after infusion, steady level acheived in the plasma by 40 minutes
- dosed 1-30 mu/min
pitocin infusion
- uterine tachysystole (5+ contractions in 10 mins)
- antidiuretic effect (can lead to severe water intoxication)
- uterine muscle fatigue (nonresponsiveness)
complications of pitocin
what is the normal uterine blood flow at term?
700-900 mL/min
what can you give if hypotension occurs due to anesthesia during labor?
IV bolus of LR and vasopressor (ephedrine)
- will typically restore maternal blood pressure and uterine flow
uterine contractions and cervical dilation result in visceral pain from what spinal levels?
T10-T12 through L1
descent of fetal head and pressure from pelvic floor, vagina and perineum generate somatic pain via what?
pudendal nerve (S2-S4)
what refers to partial or complete loss of pain sensation below T10 level?
regional anesthesia
- epidural or spinal
what are nonpharmacoloigic anesthesia options
- lamaze
- back massage
- hydrotherapy
- acupuncture
when are parenteral anesthesia options more effective?
in the early first stage of labor, when pain is more visceral and less intense
- they have very little efficacy for relief of labor pain
do opioids cross placental barrier?
yes
- can lead to neonatal respiratory depression
what is the most effective form of pain relief and is used by 60% of women in labor
epidural (loss of pain sensation below T8-10)
- catheter is placed in epidural space which allows for continuous infusion of anesthetic agents
where is the epidural space?
between L2-3, L3-4, L4-5
single shot analgesia which provides excellent pain relief for limited procedures (30-250 minutes depending on drugs used)
- limited use in labor sing it’s a single shot
spinal
- maternal coagulopathy
- heparin use within 12 hours
- untreated maternal bacteremia
- increased intracranial pressure caused by mass lesion
- skin infection over site of needle placement
contraindications for regional anesthesia
what can aid in operative vaginal delivery in women who do not have regional anesthesia?
pudendal block
- complications include intravascular injection, hematomas, and infections
what is the most common general anesthesia induction agent used?
propofol
- results in loss of maternal consciousness, MUST be accompanied by airway management
- carries 16-fold increase in risk of mortality compared to regional anesthesia
- all inhaled anesthetics readily cross placenta and have been associated with neonatal respiratory depression
