Obstetrical complications Flashcards
what is preterm labor
preterm birth/labor is defined as birth that occurs after 20 weeks gestation but before 37 weeks
diagnosis of preterm labor is _ _ accompanied with _ _ or cervical dilation of _ cm and _% effaced
uterine contractions
cervical change
OR
cervical dilation of 2cm and or 80% effaced
prematurity is the leading cause of infant _
mortality
what causes a preterm labor?
spontaneous is the most common reason
multiple gestations
preterm premature rupture of membranes
hypertension in pregnancy
cervical incompetence , uterine anomalies- fibroids, T shaped, bicornate (cant support baby)
antepartum hemorrhage
intrauterine growth restriction
_ are twice as likely as caucasions to have a preterm birth
blacks
what socioeconomic factors can lead to PTL
high stress, no access to prenatal care, poor nutrition, genetic differences?
what are some medical/OB risk factors for preterm labor
history of PTL
history of second trimester abortion
repeated spontaenous first trimester abortions
bleeding in the first trimester
infections
multiple babies in the sac
polyhradminos - more pressure on cervic
incompentent cervic
prevention of PTL is aimed at what 4 main pathways
- infection (cervical)
- placental-vascular
- psychosocial stress
- unterine stretch
what infections do we want to treat to assess the infection cervical pathway to stop PTL
bacterial vaginosis (clue cell)
group B step infections (antibiotics)
gonorrhea and chlamydia
there is a link between infection and progressive changes in the cervical _
length
cervical _ is a predictor for preterm birth risk
length
the relative risk of PTL increases as cervical length _
decreases
the relative risk of 2.4 for PTL in a cervical length of _
3.5
the relative risk of 6.2 for PTL in cervical length of
2.5
how can you routinely screen for cervical length
ulatrasound ( this is inmportant in someone with history of PTL or cold knife conization procedures)
what screening tool can we use to determine cervical length
fetal fibronectin (FFN)
this is released from the basement membrane of fetal membranes in times of disruption of membranes, cervical shortening, infection, or uterine activity
has good negative predictive value
positive predictive value is low because it could be indicating something else going on
the placental-vascular pathway begins at the time of _
implantation
the placental-vascular pathway is at the level of the _ _ _ interface
placental-decidual-myometrial interface
what components make up the placental vascular pathway
immunologic component- preeclampsia
vascular component- invasion
lower resistance connection of spiral arteries-inefficient connection
alteration in any of the components of the placental-decidual-myometrial interface (immunologic component, spiral artery connection, vascular component) may result in poor fetal _ which is a risk factor for _ as well as growth restriction and preeclampsia
growth
PTL
mental and pyschial stress are thought to induce a stress response that increases release of _ and _
cortisol and catecholamines
cortisol is released from _ _ and stimulates early placent _ _ homrone gene expression which assits in labor at term
adernal gland
corticotrophin release hormone
catecholamines affect _ _ and can cause uterine _
blood flow
uterine contractions
how can you midfy the stress-strain pathway
stress reduction and good nutrition
what causes uterine stretch in the uterine stretch pathway
increasing volume: polyhydraminos and multiple gestations
symptoms of PTL
mesutral like cramping, backache, increase in discharge/blood discharge and uterine contractions
how do you evaluate PTL
- cervical exam to assess dilation, effacement, and fetal presenting part
- evaluate for correctable problems like infection
- monitor uterine activity and fetal heart rate
- reevlauate cervix and hydrate the patient
- take cultures for group B strep and empircally treat and LABS cbc, urinalysis
- obtain ultrasound to determine fetal presentation, growth, amniotic fluid, and to rule our congenital anomalies
hydration and rest will resolve _ in about 20% of patients in PTL
contractions
but will not stop labor!
what infection should be have cultures taken when a person is admitted for PTL
group B strep
need to give them penicillin to emprically treat
how do you manage PTL
begin tocolysis if gestational age is less than 34 weeks
get magnesium sulfate
nifedipine
and prostaglandin synthetase inhibitors (idomethicin)
how does magnesium sulfate work
it competes for calcium for entry into the cell at the time of depolarization
theraputic serum levels of magnesium sulfate
5.5-7.0 mg/dL
given intravenously, can titrate down
continue magnesium sulfate therapy until recieved both doses of _
steroids
magnesium sulfate is important in _
neuroprotection against cerebral palsy
magnesium sulfate is given when patient is at risk for delivering within _ days. and is currently given if less than _ weeks
7 days of delivering
less than 32 weeks gestation
side effects of magnesium (maternal)
feeling warm
N/V
respiratory depression at levels of 12
cardiac arrest at levels greater than 30
side effects of magnesium sulfate (neonate)
loww of muscle tone
drowsiness
lower apgar score
what is nifedepinde?
an oral tocolytic to supress preterm labor
MOA of nifedipine
inhibits the slow inward current of calcium during the second phase of action potential
side effects of nidedipine (baby and mom)
hypotension
tachycardia
headache
what is a prostaglandin synthetase inhibitor - ideomethacin
a pgf2a inhibitor that inhibits prostaglandin production that induces myometrial contractions
it is only used on short term basis (extreme prematurity)
indomethacin can be given _ or _
orally or rectally
indomethacin can result in _ and can cause premature closure of fetal _ _ and result in pulmonary hypertension and heart failure
oligohydraminos
ductus arteriosis
infants exposed to indomethacin are greater risk of _ and _
necrotizing enterocolitis and intracranial hemorrhage
_ are used to mature premature fetal lungs
glucocorticoids (betamethasone and dexmethasone)
glucorticoids are given between _ and _ weeks gestation
24 and 34
glucorticoids reduce mortality and incidence of _
respiratory distress syndrome, NEC, IVH (intraventricular hemorrhage)
how is betamethasone and dexmathasone given and how long do they last
betamethasone : 2 doses given 24 hours apart
dexamathasome: 4 doses 12 hours apart
7 days effects last
a single course of _ is recommended for pregnant women between 34 and 37 weeks of gestation at risk of preterm birth within 7 days and who have not recieved a course of antenatal corticosteroids
betamethasone
the lowewr limit of viability is _ weeks or _ grams
24 weeks and 500 grams
how do you deliver a preterm baby in vertex position
vaginal delivery is proffered
how do you deliver a preterm baby thats in the breeched postion
C section because there is an increased risk cord prolapse or compression or head entrapment in the cervix
how can we prevent PTL
progesterone IM weekly from 16 weeks to 36 weeks -only used in people with previous history of sponteneous PTL
relaxes the smooth muscle
what do we use in women with a shortned cervix
vaginal progesterone
or pessary-arabian
what is premature rupture of membranes (PROM)
premature rupture of membranes before the onest of labor at any gestational age
what are the risk factors for PROM
history of PROM
infections
short/incompentent cervix
smoking
nutritional def.
second and third trimester bleeding
how do you diagnose PROM
based on history
- loss of fluid
- -confirmation of amniotic fluid in vagina
why should you not cehck the cervic of a presumed ruptured preterm patient
it increases the risk of infection
PROM rupture is confirmed with?
sterile speculum
what test detect amniotic fluid
amnisure- detects PAMG-1 in amniotic fluid
can be done at any age
not affected by urine, semen, infection, or small amount of blood
cannot use if recent intercourse, digital vaginal exam of significant blood
what 3 tests confirm PROM
pooling
nitrazine paper (will turn blue)
ferning
ultrasound amniotic fluid volume to aid in fiagnosis
what can cause a false positive on nitrazine test
urine, semen, cervical mucus, blood, vaginitis
what can cause a false negative on nitrazine paper
remote PROM with no remainng fluid
minimal leakage
an intact amniotic sac provides a barrier to infection: specifically what infection
chorioamnionitis
when is an infection of hte membranes and fetus
PPROM (premature premature rupture of membranes ) is associated with about 30% of preterm _
labors
what are some risks that PPROM can cause in the mother
endomymetritis
sepsis
failed induction due to an unfavorable cervix
management of PPROM depends on what?
- gestational age at time of rupture
- amniotic fluid index
- fetal status
- maternal status
if the gestational age is less than 24 weeks and there is PPROM this may lead to?
pulmonary hypoplasia and fetal structural abnormalities
if the amniotic fluid index is a value less than 5 or no _cm deepest vertical pocket is found this is called _
oligohydraminos
no fluid is anhydramnios
when there is PPROM we put them in inpatient care and try to continue pregnancy until lung profile is mature and deliver them at _ weeks
34 (regardless of fetal lung maturity, could be earlier if there is an a infection)
in a patient with PPROM you must monitor for chorioamniotis: what are the symptoms of this
maternal temperature greater than 100.4
fetal or maternal tachycardia
tender uterus
foul smelling amniotic fluid/purulent discharge
what should you conservatively give someone with PPROM
antibiotcs to prolong the latency period until delivery (decrease their chances of getting an an infection) - ampicillin and erythromycin/azithromycin followed by 5 days of amoxicilin and erythromycin
tocolytics if there are contractions to delay labor and get steroid onboard
steroids up to 34 weeks to reduce risk of RDS
no real place for them to be in outpatient management
if lamellar bodies are present, l/s ratio is greater than 2 and phosphatidylglycerol is present what does this mean?
the lungs are mature
what is intrauterine fetal growth restriction
when the fetal weight or abnominal circumference of a newborn is below 10% for any gestational age
what is SGA (small for gestational age)
birth waeight at the lower extreme of normal birth weight distribution (after delivery)
growth restricted fetuses are at risk for?
meconium aspiration
hypoxis
polycythemia
hypoglycemia
adult onset of conditons like hypertension, diabetes, CAD, stroke
intrauterine growth restriction can be caused by 3 main categories:
- maternal
- placental
- fetal
what are some maternal causes of IUGR
poor nutritional intake/low maternal body weight
smoking
alchoholism
antiphospholipid syndrome **
teratogen exposure
collage vascular disease/autoimmune disorders
placental causes of IUGR
defective trophoblast invasion
insufficent substrate transfer
giving placental insufficency: due to renal disease, HTN, velamtonous cord, preexisting diabetes
fetal causes of IUGR
infections: TORCH
toxoplasmosis
other infections
rubella
cytomegalovirus
herpes
also listeriosis
chromosomal abnormalities, congeital anomalies, multiple gestations (fight for room to grow)
toxoplasmosis can cause _ in the infant
hydrocephalus
how do you diagnose IUGR
physical exam
ultrasound
direct studies
other
physical exam: fundal height
ultrasound: biometry
direct studies: amniocentesis
other: doppler studies
in IUGR serial _ _ measurements is a primary screening tool
fundal height
(from the top of the uterus to the pubic bone)
if the fundal height lags more than _ cm behind gestational age then order an _
3cm
ultrasound
ultrasound is used routeinly for high risk conditions that predisopse to IUGR like?
HTN, renal disease, diabetes, drug use, Antiphospholipid syndrome, lupus
what measurements are we taking during ultrasound to diagnose IUGR
biparietal diameter
head cicumference
abdonimal circmference
head-abdominal circumference
femoral length
femoral length to abdominal circumference ratio
amniotic fluid volume
fetal weight
umbilical and uterine artery doppler
how do you manage IUGR pre-pregnancy?
optimize disease process control (like if they were diabetic or have HTN control these diseases)
how do you manage IUGR during pregnancy
decrease any modifying factors like stop smoking; and improve nutrition
what is the goal with managing IUGR
to deliver before fetal compromise byt after fetal lung maturity
what do you monitor in a baby with IUGR during pregnancy
non-stress test twice weekly
biophysical profile
doppler studies of umbilical artery
what is a nonstress test?
testing the babies heart rate with an external transducer while the mom is in a left lateral recombent position. a good stress test is 15bpm accelerations lasting at least 15 seconds. It usually takes about 20 minutes.
what does the biophysical profile contain
NST (which can be omitted if the other 4 portions are normal)
fetal breathing movements
fetal movements
fetal tone
amniotic fluid volume - greater than 2cm
score of 8-10 is normal
uses ultraasound
30 minutes long
doppler study of the umbilican artery in IUGR
depicts any vascular inmpedence in a fetus
shows umbilical flow velocity, waveform is usually high velocity diastolic flow
in IUGR there is a decrease in umbilical artery diastolic flow (can be absent or reversed)
- if flow is reversed this is not a good sign and mortality is high
if you suspect IUGR and the ultrasound is normal what do you do?
if the ultrasound shows IUGR between 3rd and 10th percentile with normal dopplers what do you do?
if the ultrasound shows IUGR less than 3rd percentile what should you do
early delivery is indicated in cases of ?
no intervention
deliver between 38-39 weeks
deliver at 37 weeks
absent/reverse umbilical flow
you can use corticosteroids for lung maturity if less than 37 weeks
is IUGR an indication for c-section?
no but some fetuses may have less reserve and tolerance for laboe, monitor them!
after birth you should monitor a IUGR neonate for what?
monitor blood glucoase- because they have less hepatic glycogen stores
monitor respiratory statius - RDS is very common
what is a post term pregnancy?
this is a pregnancy that continues past 42 weeks
occurs in about 10% of pregnancies
post term pregnancies have a higher perinatal mortility rate and can lead to _ syndrome
postmaturity
what is post maturity syndrome?
this is when the placenta ages and infarcts which leads to fat loss, long fingernails, abundant hair, and dry peeling skin in a baby
in a post term pregnanct is not complicated by placental insufficeincy the fetus is at risk for _, there could be abnormal _, shoulder dystocia, and c-section
macrosomia (greater than 4500 grams)
abnormal labor
why do post-term pregnancies occur
unsure dates, fetal adrenal hypoplasia, anecephalic features (need normal structures to have a functional labor)
placental sulfatase deficiency
extrauterine pregnancy
what is placental sulfatase deficinecy
an x linked disease that prevents conversion of sulfated estrogen precursors
at 41 weeks in post partum pregnancy you should do what
begin fetal testing with NST twice weekly and biophysical profile
if any testing is abnormal or there is no amniotic fluid you should induce labor
at 42 weeks in a post term pregnancy you should
just induce labor
induction of labor at _ weeks is the preferred plan on care in a post-term pregnancy
41
what is intrauterine fetal demise
fetal death after 20 weeks gestation but before the onset of labor
what causes an intrauterine fetal demise
most of the time the cause is unknown
could be : HTN, diabetes, cholestasis of pregnancy, umbilical cord accident
infections, hemorrhage, antiphopholipid antibodies
thrombophilias
diagnosis if IUFD
complains of absence of fetal movements, no doppler fetal heart tones
confirm IUFD by?
ultrasound with lack of fetal acivity and absence of fetal cardiac activity
you can watch IUFD up until _ weeks because spontaneous delivery will usually occur within 3 weeks of fetal demise
28
you can induce labor in IUFD and this will require cervical ripening with prostaglandins, _, misprostol, oxytocin
laminaria
patients with IUFD are at high risk for _ and need to follow complete blood count, fibrinogen levels, and PT/PTT/INR
disseminated intravascular coagulopathy
follow up of IUFD includes?
TORCH titers
fetal chromosome studies and fetal autopsy which must be consentede to
listeria cultures
anticardiolipin antibodies
(susbequent pregnancies are at a greater risk for IUFD so antenatal testing should be done)
