Normal Labor Flashcards
progressive cervical effacement and dilation from regular uterine contractions occurring at least every 3 minutes and last 30-60 sec each
labor
Braxton Hicks (false labor)
common during weeks 4-8 - irregular/unpredictable uterine contractions
signs of false labor
- Braxton Hicks contractions - irregular, more in abdominal region, repositioning can alter
- no progression of labor
- not associated w/ cervical dilation or effacement
- membranes not ruptured (no bloody show)
hormones that inhibit labor
progesterone and relaxin
hormones that stimulate growth
estrogen and prostaglandins
hormones that stimulate contractions
oxytocin and prostaglandins
most important anatomic factor in labor
fetal skull size
largest part of fetal skull
supraoccipitomental (13.5cm)
structures of true pelvis
pubis anterior, sacrum, coccyx, ischium laterally
false pelvis
above true pelvis - supports uterus
fetal head enters this plane 1st
pelvic plane
largest plane
plane of greatest diameter
MC site of low transverse arrests
plane of least diameter
ischial tuberosities B/L - site of low pelvic arrest
pelvic outlet
pelvic shapes
classic shape, 50% of women, spacious and cylindrical, widest transverse diameter
gynecoid
(most favorable)
pelvic shapes
long narrow inlet w/ wide AP diameter, 20% of women, fetal head traverses in AP diameter
anthropoid
“oval shaped”
pelvic shapes
bases on dimensions, most limited for fetal descent, side walls converge, arrest of descent common, 30% of women
android
“heart shaped”
pelvic shapes
“flattened” gynecoid pelvis, narrow AP - fetal head must engage in transverse diameter, 3% of women
platypelloid
“wider than taller shape”
3 P’s of Labor Determining Transit Time
- Power - uterine activity
- Passenger - size, lie, presentation, attitude, position, station
- Passageway - female pelvis types
2 exam types during labor
- obstetric
- fetal position and lie
- Leopold maneuvers, US
- cervical
- determine phase of labor/progression
- 5 items
- dilation
- effacement
- station
- cervical position
- cervical consistency
dilation
how open cervix is at internal os
(closed - 10cm)
- nulliparous: effacement before dilation
- multiparous: dilation before effacement
- rate of dilation
- nullliparous 1-1.2 cm/hr
- multiparous 1.5 cm/hr
effacement
how thin cervix is between internal and external os
(normally 3-5cm)
measured in % - 100% is paper thin/ready to deliver
station
relationship of head to ischial spines
- zero station - presenting part level w/ spines
- neg. station - above
- pos. station - below
- ranges -5 to +5 (but typically -3 to +3)
cervical position
posterior, mid, anterior
cervical consistency
firm / soft / in-between
measurement to determine if cervix favorable for spontaneous delivery
Bishop score
(8 is favorable)
intervening to increase the already present contractions
augmentation
attempt to begin labor in a non-laboring patient
induction
maternal indications for induction
- pre-eclampsia
- hypertension
- deteriorating/uncontrolled diabetes
- placental abruption
- previous still birth
fetal indications for induction
- post dates (usually T+10)
- IUGR
- rhesus disease
- intrauterine death
- placental insufficiency
induction contraindications
- cephalopelvic disproportion
- malpresentation (unless face or breech)
- fetal distress
- placenta previa
- cord presentation
- vasa praevia
- pelvic tumor
cautions for induction
- grand multiparity (6+)
- previous c-section (risk of uterine rupture)
- previous precipitate labor (risk of hyperstimulation)
First state of labor
onset true labor to complete dilation of cervix
Second state of labor
complete dilation of cervix to birth of baby
(if prolonged may require operative delivery -
forceps or vacuum)
Third state of labor
birth of baby to delivery of placenta
(oxytocin to reduce blood loss)
Fourth stage of delivery
delivery of placenta to stabilization of patient
2 phases of stage 1 labor
- latent - cervical effacement and early dilation (3-4cm)
- active - rapid cervical dilation beginning at 4cm w/ active uterine contractions
- 1cm/hr primiparous
- 1.2cm/hr multiparous
duration of stage 2 labor
30min - 3hours
normal changes in babies head d/t delivery
- molding - alteration of cranial bones d/t compression
- caput - localized edema
6 cardinal movements of labor
- engagement
- descent
- flexion
- internal rotation
- extension
- external rotation
6 cardinal movements
widest presenting part drops into pelvic inlet
engagement
6 cardinal movements
dropping of fetal presenting part further into pelvis
descent
6 cardinal movements
dropping of chin toward fetal chest to present smallest diameter to maternal inlet
flexion
6 cardinal movements
presenting parts rotate to AP diameter
internal rotation
6 cardinal movements
occiput reaches symphysis/vaginal canal shifts upward - crowning when head encircled by vulvular ring
extension
6 cardinal movements
delivered head returns to original position to align w/ back and shoulders
external rotation
6 cardinal movements + 1
delivery of rest of fetus - anterior shoulder follows similar rotation under pubis
expulsion
management of first stage
- patient ambulation or lateral recumbent position
- IV fluids
- labs
- maternal monitoring
- analgesia
- fetal monitoring
- uterine activity
- vaginal examinations
- amniotomy
management of second stage
- maternal position- avoid supine
- bearing down
- fetal monitor: HR continuously or every 5 min
- vaginal exam: every 30 min
- delivery:
- supine or left lateral position
- episiotomy
- Ritgen maneuver
- clear airway when head delivered
- umbilical cord check
- anterior shoulder then body delivered
- cord clamping delayed 1-2 min
Ritgen Maneuver
upward pressure to chin by posterior hand covered
w/ sterile towel
while suboccipical region of head held against symphasis
management of third stage
- inspect vagina and cervix for lacerations & repair
- IV Pitocin - prevent hemorrhage
- deliver placenta
- signs of separation
- fresh show of blood
- umbilical cord lenghthens
- fundus rises
- uterus becomes firm & globular
- signs of separation
- uterine massage - prevent atonicity
- examine placenta for full removal and abnormalities
management of fouth stage
- monitor HR, BP, uterine blood loss to prevent post-partum hemorrage
- patient massaging uterus
period following delivery of baby and placenta to 6 weeks postpartum
puerperium
normal aspects of puerperium
- organs and physiology return to pre-preg. state
- uterus involution - cervix firms
- uterine discharge
- lochia rubra
- lochia serosa
- lochia alba
- r/o endometriosis if foul-smelling lochia
- menstrual flow returns in 6-8 weeks
APGAR
- appearance (color)
- pulse (HR)
- grimace (muscle tone)
- activity (reflex irritability)
- respirations (RR)
APGAR scoring scale
0 1 2
color blue centerpink all pink
HR 0 <100 >100
resp. none weak cry vigorous cry
tone none some flex all flexed
reflex none some motion crying, withdrawal
APGAR score interpretation
scored at 1 and 5 minutes
- 8-10: no concerns
- 4-7: watch closeley and repeat at 10 min**
- 0-3: resuscitate
how to stimulate breathing after delivery
flick soles or rub back
procedure if evidence of meconium passed
intubate and suction trachea before stimulating baby
when do you initiate positive pressure ventilation
gasping, apnea, HR < 100 bpm
descision made in first 30-60 seconds after birth
fetal heart rates during labor
(normal, tachycardia, bradycardia)
110-160
>160
<110
steps in fetal monitoring baseline assessment
- determine baseline FHR
- variability - changes in freq/amp w/ baseline
- normal short-term variability 6-25/min
- below 5 - fetal distress
- changes related to contractions
- no change
- acceleration
- deceleration (early, late, variable, prolonged)
fetal heart rate monitoring -
prolonged flat baseline indicates
short term variability
fetal acidosis
fetal heart rate monitoring -
normal is 3-10 cycles per min, abnormal indicates
long term variability
metabolic derangement
fetal heart rate monitoring -
early deceleration indicates
fetal head engagement
fetal heart rate monitoring -
late deceleration indicates
uteroplacental insufficiency
(repeated represents fetal hypoxia and acidosis)
fetal heart rate monitoring -
variable decelerations indicate
umbilical cord compression
non-pattern signs of fetal distress -
prolonged fetal tachycardia indicates
maternal fever and infection
non-pattern signs of fetal distress -
early meconium passage (before membrane rupture) increases risk of
fetal aspiration
non-pattern signs of fetal distress -
late meconium passage (2nd stage of labor) indicates
umbilical cord compression or hypertonic uterus
amniocentesis
when performed and what it tests
16-20 weeks via 22ga needle w/ US guidance
- fetal chromosome abnormalities
- AFP for neural tube defects
- prenatal infections
- 3rd trimester to assess lung maturity
- remove excessive fluid in polyhydramnios or twins
20mL fluid used
similar to amniocentesis
what it is, when it’s done
chorionic villus sampling
- week 10 (earlier than amnio)
- sample from placenta through cervix or abdomen
- slightly less sensitive for genetic abnormalities
procedures to close cervix
- cerclage
- circumferential suture at 13-16 weeks
- McDonald
- simple purse-string suture near cervicovaginal junction
4 indications for operative vaginal delivery
(forceps, suction, c-section)
- prolonged 2nd stage labor
- suspicion of immediate impending compromise
- stabilize head after breech delivery
- shorten 2nd stage for mom’s benefit
birth via laparotomy then hysterotomy
cesarean section
1’ - first time hysterotomy
2’ - uterus w/ 1+ prior hysterotomy incisions
reasons for increasing c-section
- fewer children - more nulliparas births
- avgerage maternal age rising
- more electronic fetal monitoring
- more breech fetuses
- decrease in forcep and vacuum deliveries
- more inductions
- rise in obesity
- increases for preeclampsia
- VBAC has decreased
- more elective c-sections
