complications of labour Flashcards
how do preterm labour and cervical insufficiency differ
PTL–> preterm contractions with associated cervical change
cervical insufficiency–> silent, painless dilatation and effacement of the cervix
both can result in preterm delivery which is the leading cause of fetal morbidity and mortality in the USA
define preterm infant
born before 37 weeks GA
define low birth weight infant
less than 2500 g
preterm infants are at greater risk for what diseases
RDS hyaline membrane disease intraventricular hemorrhage sepsis necrotizing enterocolitis
list risk factors associated with PTL
preterm rupture of membranes chorioamnionitis multiple gestation uterine anomalies (bicornuate uterus) previous preterm deliveries maternal prepregnancy weight less than 50 kg placental abruption maternal disease (preeclampsia, infections, intra-abdominal disease, surgery) low socioeconomic status
what is tocolysis
an attempt to prevent contractions and the progression of labuor
what tocolytic is approved by the FDA
ritodrine (a beta mimetic agent)
how long do tocolytics prolong gestation for
48 hours
what is the benefit for tocolytic use
allow time for treatment w steroids to enhance fetal lung maturity and reduce the risk of complications from preterm delivery
in which cases should you allow PTL to progress rather than using tocolytics
chorioamnionitis
non reassuring fetal testing
significant placental abruption
these are all ABSOLUTE indications to allow labour to progress
what is the goal of a tocolytic
to decrease or halt the cervical change resulting from contractions
what can you use to decrease the number and strength of contractions if there is no associated cervical change
hydration –> a dehydrated patient has increased levels of vasopressin or ADH (synthesized with oxytocin)–> ADH differs from oxytocin by only one amino acid and thus it may bind with oxytocin receptors and lead to contractions
hydration thus reduces ADH and may decrease contractions
name two beta mimetics used as tocolytics
ritodrine
terbutaline
only increase gestation by about 24-48 hours
side effects of tocolytics
tachycardia
headaches
anxiety
pulm edema
rare–> maternal death
how is ritodrine given
continuous IV therapy
how is terbutaline given
0.25 mg SC, loaded q20 min x 3 doses and then q3-4 maintenance
why should you not use terbutaline beyond 24-48 hours
can cause maternal death and cardiac events including tachycarida, hyperglycemia, hypokalemia, cardiac arrhythmias, pulm edema and myocardial ischemia
how does magensium sulfate act as a tocolytic
decreases uterine tone and contractions by acting as a calcium antagonist and a membrane stabilizer
can stop contractions but has not been shown to increase gestational age of delivery
side effects of magnesium sulfate
headaches
flushing
fatigue
diplopia
generally less severe than ritodrine or terbutaline
at toxic doses–> reduced DTRs, resp depression, hypoxia, cardiac arrest
how do you dose magnesium sulfate as a tocolytic
6 g bolus over 15-30 min and then maintained at a 2-3 g/hour continuous infusion
slower infusion in case of renal insufficiency because magnesium cleared by kidneys
name a calcium channel blocker used as a tocolytic
nifedipine
how do Ca channel blockers like nifedipine work as tocolytics
decrease influx of calcium into smooth muscle cells thereby diminishing uterine contractions
side effects of CCB nifedipine
headaches
flushing
dizziness
how do you dose nifedipine
10 mg loading dose q15 min for first hour or until contractions have ceased
maintenance hose of 10-30 mg q4-6h as tolerated according to BP
what effect do prostaglandins have on contractions
increase intracellular levels of calcium and enhance myometrial gap junction function thereby increasing myometrial contractions
commonly used to induce labour and heighten contractions in post partum patients with uterine atony
name a prostaglandin inhibitor used as a tocolytic
indomethacin (NSAID) blocks COX enzymes and decreases prostaglandin levels
minimal maternal side effects but has a variety of fetal complications including premature constriction of the ductus arteriosus, pulm HTN and oligohydramnios
define preterm rupture of membranes
rupture of membranes before week 37
define premature rupture of membranes
rupture of membranes before onset of labour
define PPROM
both premature and preterm rupture of membanes
define prolonged rupture of membanes
ROM lasting longer than 18 hours before delivery
without intervention, what % of women with preterm ROM will go into labour within 24 hours? 48 hours?
within 24 hours–50%
within 48 hours–75%
why might you not want pregnancy to continue too long after PPROM, even if they are premature?
higher risk of chorioamnionitis, abruption and cord prolapse
how do you diagnose preterm ROM
most patients complain of a gush of fluid from the vagina but any increased vaginal discharge or complaints of stress incontinence should be evaluated to rule out ROM
dx made by obtaining hx of leaking fluid, pooling on speculum exam and positive nitrazine test and fern tests
at what gestational age is the risk of prematurity the same as the risk of infection with PPROM
between 32-36 weeks
before this, risk of prematurity drives management of PPROM
after this, the risk of infection drives management of PPROM (and motivates delivery)
most common practice is to deliver at 34 weeks GA
what role do antibiotics have in the management of PPROM
strong evidence suggests that they lead to a longer latency period prior to onset of labour –>
AMPICILLIN with or without ERYTHROMYCIN is recommended in the setting of PPROM
do you use tocolytics in PPROM
controversial–> seem to have little benefit and may be harmful in setting of chorioamnionitis but many places will use tocolysis for 48 hours in order to give betamethasone
what is the most common concern with PROM
chorioamnionitis
what should you do for a woman who has prolonged ROM
antibiotics–> also for women with unknown GBS status
then should induce labour if between 34-36 weeks GA
what is a common cause of failure to progress in labour
CPD
name the 4 dominant types of maternal pelvis
gynecoid
android
anthropoid
platypelloid
define breech presentation and what is the incidence
buttocks first
3-4% of all singleton deliveries
risk factors for breech delivery
previous breech delivery
uterine anomalies
polyhydramnios
oligohydramnios
multiple gestation
PPROM
hydrocephaly
anencephaly
what are two complications of a vaginal breech delivery
prolapsed cord and entrapment of the head
what are the three types of breech presentation
frank
complete
incomplete/footling
define frank breech presentation
flexed hips, extended knees with feet near fetal head
define complete breech presentation
flexed hips but one or both knees are also flexed with at least one foot near the breech
define incomplete/footling breech presentation
one or both hips not flexed so that foot or knee lies below the breech in the birth canal
what are the management options for breech presentation
- external cephalic version of the breech
- trial of vaginal breech delivery
- elective C/S
what is the process of external cephalic version to treat breech presentation
manipulation of the breech infant into a vertex position–> rarely performed before 36-37 weeks GA because could do it spontaneously before this time
also risk for delivery after version secondary to abruption or ROM
usually done without anesthesia–> if unsuccessful, can try again with epidural anesthesia at 39 weeks and then either induce labour if successful or no then have C/S
list complications of vaginal breech delivery
cord prolapse
entrapment of fetal head
fetal neurologic injury
what are the criteria for a trial of vaginal breech delivery (vs C/S)
favorable pelvis
flexed head
estimate fetal weight between 2000-3000 g
frank or complete breech
contraindications to trial of vaginal breech delivery
nulliparity
estimated fetal weight above 3800 g
incomplete breech presentation
what presentation is common in anencephalic fetuses
face
can you deliver a brow presentation vaginally
no unless head is unusually small–must convert to face or vertex to deliver
define compound presentation
fetal extremity presenting alongside the vertex or breech
rate of compound presentation increases with prematurity, multiple gestation, polyhydramnios and CPD
what is a common complication of compound presentation
umbilical cord prolapse
how do you manage a compound presentation
if upper extremity presenting with vertex then often can be gently reduced and delivery vaginally
if lower extremity with vertex–> less likely to deliver vaginally
footling presentation (breech) is indication for cesarean
should always suspect and monitor for umbilical cord prolapse
how do you manage a shoulder presentation
unless converts spontaneously, must do C/S because of increase risk of cord prolapse, uterine rupture and difficulty of vaginal delivery
what is the best fetal position for passing through pelvic inlet
occiput anterior (OA)
LOA and ROA are also normal and commonly rotate to OA by late first stage or second stage
define malposition of the fetus
OT or OP
have higher rate of C/S
what intervention is more associated with malposition
epidural use –> reduces tendency to rotate to OA from OP or OT (doesnt cause them)
what is the most common position of the fetus at onset of labour
LOT or ROT
from transverse position, cardinal movement of internal rotation usually converts the fetus to the OA position
what are the options for deliveries that have prolonged second stage and OT or OP position of the fetus
delivery via forceps or vacuum in OP position
rotation with forceps
manual rotation
in either OP or OT, if attempt at rotation or operative delivery fails, C/S commonly required
OP cases delivery spontaneously 50% of the time but OT rarely delivery vaginally and must rotate to either OP or OA to delivery vaginally
list possible obstetric emergencies
fetal bradycardia
maternal hypotension
uterine rupture
seizure
shoulder dystocia
define a prolonged deceleration
any time the FHR is below 100-110 bpm for longer than 2 minutes
define FHR bradycardia
FHR below 100-110 bpm for longer than 10 min
what complications are associated with prolonged decels/fetal brady
placental abruption
cord prolapse
uterine tetanic contractions
uterine rupture
PE
amniotic fluid embolus (AFE)
seizure
poor fetal outcome
how do you categorize etologies of FHR decels
preuterine
uteroplacental
post-placenal
what are some preuterine causes of FHR decels
any event leading to maternal hypotension or hypoxia–> seizure, AFE, PE, MI, respiratory failure or recent epidural or spinal placement leading to hypotension
what are some uteroplacental causes of FHR decels
placental abruption
placental infarction
hemorrhaging previa
uterine hyperstimulation
what are some post placental causes of FHR decels
cord prolapse
cord compression
rupture of fetal vessels (vasa previa)
what should you do first when you notice a decel
check to make sure youre not picking up moms HR with a fetal scalp electrode
describe an algorithm to diagnose the etiology of FHR decels
- look at mother for signs of respiratory compromise or change in mental status–> will commonly diagnose seizures, PE, AFE
- while putting on a glove for a cervical exam, assess maternal BP and HR–> will diagnose maternal hypotension (common after epidural placement and a potential cause of FHR decels) and will also tell you if you’re actually getting maternal HR
- immediately before exam, look to see how much vaginal blood is passing–> if increased, placental abruption and uterine rupture should be considered
- examine patient with one hand on maternal abdomen and one hand vaginally feeling for cervical dilation, fetal station and prolapsed umbilical cord–> abdo hand should feel for uterine hyperstimulation and fetal parts outside the uterus
- if fetal station is dramatically lower than expected, prolonged HR decel may be due to rapid descent and vagal stimulation
- if fetal station is much higher than expected, uterine rupture should be suspected
- if cervix is fully dilated and the fetus is in the pelvis, operative vaginal delivery can be performed if the FHR decels do not resolve
what is the standard initial management for a prolonged FHR decel
- patient moved to L or R lateral decubitus position to resolve a decel secondary to compression of the IVC leading to decreased preload or compressed umbilical cord
- oxygen by face mask commonly administered to mother in case hypoxia is an issue
- examination performed (see previous card) –> individual etiologies diagnosed and treated appropriately
how do you manage maternal hypotension causing FHR decels
aggressive IV hydration and ephedrine
how do you treat maternal tetanic uterine contraction leading to FHR decels
nitroglycerin usually SL
(and/or terbutaline
how do you treat cord prolapse causing FHR decels
emergent C/S –> lift fetal head to avoid compression of prolapsed cord
how do you treat previa causing FHR decels
urgent C/S
how do you treat abruption causing FHR decels
if remote from delivery, C/S
after how long of FHR decels should you move a patient into the OR
after 4-5 minutes of decels
if persists in the OR, at around 8 minutes of decel total, should plan emergent C/S –> goal of delivery of fetus in this setting is to be within next 2-4 minutes
*sterile technique may not be possible
define shoulder dystocia
difficulty delivering shoulders, particularly because of impaction of the anterior shoulder behind the pubic symphysis, after delivery of the head
risk factors for shoulder dystocia
fetal macrosomia (weight over 4000 g)
preconceptional and gestational diabetes
previous shoulder dystocia
maternal obesity
postterm pregnancy
prolonged second stage of labour
operative vaginal delivery
fetal complications of shoulder dystocia
fractures of the humerus and clavicle
brachial plexus nerve injuries (Erb palsy)
phrenic nerve palsy
hypoxic brain injury
death
how is shoulder dystocia diagnosed
when routine obstetric maneuvers cannot deliver the fetus
“turtle” sign–> incomplete delivery of the head or the chin is tucking up against the maternal perineum
what should you do once you ID a shoulder dystocia
labour and delivery alert should be called
pediatric team should be called
someone needs to run the shoulder dystocia emergency (similar to a code)
someone should be assigned to keep track of time, as dystocia can lead to entrapment and complete compression of the umbilical cord–> *delivery in less than 5 minutes is imperative
two individuals should be assigned to hold the patients legs and one person to give suprapubic pressure
do the specific maneuvers to deliver shoulder dystocia (see another card)
if infant is still undelivered–> generous episiotomy, or cut or fracture the clavicle
if all else fails–> Zavanelli maneuver
what are the maneuvers for delivering a fetus with shoulder dystocia
- McRoberts maneuver–> sharp flexion of the maternal hips that decreases the inclination of the pelvis and thus increases the AP diameter can free the anterior shoulder
- suprapubic pressure–> pressure applied just above the maternal pubic symphysis at an oblique angle to dislodge the anterior shoulder from behind the pubic symphysis
- Rubin maneuver–> pressure on an either accessible shoulder toward the anterior chest wall of the fetus to decrease the bisacromial diameter and free the impacted shoulder
- wood’s corkscrew maneuver–> pressure behind the posterior shoulder to rotate the infant and dislodge the anterior shoulder
- delivery of the posterior arm/shoulder–> delivery of the posterior arm by sweeping the posterior arm across the chest to allow the bisacromial diameter to torate to an oblique diameter of the pelvis and anterior shoulder to be freed
what is the Zavanelli maneuver
in the case of persistent shoulder dystocia
place the infants head back into the pelvis and perform a C/S
in which patients should you suspect uterine rupture
in setting of FHR decels in patients with prior uterine scars
may feel a “popping” sensation or experience sudden abdo pain
common etiologies of maternal hypotension
vasovagal events
regional anesthesia
overtreatment with antihypertensives
hemorrhage
anaphylaxis
AFE
how should you treat anaphylaxis in a pregnant woman
benadryl and epinephrine
how do you make the definitive diagnosis of AFE
finding fetal cells in the maternal pulm vasculature at autopsy
what is one of the key ways to distinguish between seizures and a vasovagal event
presence of a post-ictal period after the event
what should you do if a patient has a seizure on labour and delivery
full pre-eclampsia workup, tox panel, chem panel, and head CT when safe to leave ward
neuro consult indicated
manage acutely with ABC management and anti-seizure meds
what is the anti-seizure med of choice in pregnancy
magnesium sulfate
describe a plan of action for managing a seizing patient on labour and delivery
- access and establish airway and vital signs including oxygenation
- assess FHR or fetal status
- bolus magnesium sulfate, or give 10 g IM
- bolus with lorazepam 0.1mg/kg, 5-10 mg at no more than 2 mg/min
- load phenytoin 20 mg/kg, usually 1-2 g at no more than 50 mg/min
- if not successful, load phenobarbital 20 mg/kg
- lab tests–> CBC, metabolic panel, AED levels, tox screen
- if non reassuring fetal testing, move to emergent delivery
