medical complications in pregnancy Flashcards
Pregnancy induced HTN (PIH)
HTN that develops AFTER 20 wks of gestation in the absence of proteinuria & returns to nml postpartum.
Chronic HTN
HTN present before 20th wk of pregnancy or HTN present before pregnancy
mild HTN
systolic >/= 140-180 mmHg or
diastolic >/= 90-100 mmHg or
both
severe HTN
SBP >/= 180 mmHg or
DBP >/= 100 mmHg
what is the major risk factor w/ chronic HTN?
development of preeclampsia/ eclampsia later in pregnancy
preeclampsia
develop of HTN w/ proteinuria & edema fter 20wks gestation
BP in preeclampsia
SBP > 140 mmHg or DBP > 90 mmHg
2 occasions > 6 hrs but < 7 days apart
after 20 wks gestation w/ previously nml BP
Proteinuria in preeclampsia
urinary excretion of 0.3 g protein or higher in 24 hr urine or >/= 1+ protein on UA dipstick
severe preeclampsia
SBP > 160 mmHg or DBP > 110 mmHg marked proteinuria -> 5g/24 hr urine or 3+ on 2 dipstick of random urine samples collected at least 4 hrs apart oliguria-> < 500 mL in 24 hrs cerebral/visual distrubances (HA & scotomata) pulmonary edema/cyanosis epigastric/RUQ pain evidence of hepatic dysfunction thrombocytopenia IUGR
eclampsia
presence of convulsions (grand mal seizures) in a woman w/ preeclampsia not explained by neuro d/o
most cases occur w/in 24 hrs of delivery but can also occur 2-10 days postpartum
risk factors for preeclampsia
nulliparity age 35 yo new paternity FH of preeclampsia CRD, chronic HTN prolonged interpregnancy interval antiphospholipid syndrome DM multi-fetal gestation high BMI connective tissue d/o (RA, SLE) vit D insufficiency?
what is the predominant pathophysiological finding in preeclampsia
maternal vasospasm
what are some potential causes of maternal vasospasm
vascular changes
hemostatic changes
changes in prostanoids
dysfunctional changes in endothelium-derived factors
lipid peroxide, free radicals & antioxidant release
vascular changes
theorized that a shallowly implanted placenta becomes hypoxic-> upregulates placental inflammatory mediators->acts on vascular endothelium
- decreased musculature in spinal arterioles leads to development of low-resistance, low pressure, high-flow system
- inadequate maternal vascular response
- endothelial damage w/in vessels
Hemostatic changes
- increased platelet activation w/ increased consumption in microvasculature
- endothelial fibronectin levels are increased & anti-thrombin III 7 a2- antiplsmin levels are decreased (reflects endothelial damage)
changes in prostanoids
-prostacycline (PG12) & thromboxane (TXA2) increased during pregnancy
PG12 promotes what?
vasodilation
TXA2 promotes what?
vasoconstriction
platelet aggregation
during pregnancy, balance is in favor of PG12 or TXA2?
PG12
pts w/ preeclampsia, balance is in favor of PG12 or TXA2?
TXA2
dysfunctional changes in endothelium-derived factors (may be placental in origin)
nitric oxide (potent vasodilator) is decreased–may explain evolution of vasoconstriction
lipid peroxide, free radicals & antioxidant release
lipid peroxide & free radicals implicated in vascular injury & increased in women who develop preeclampsia
decreased antioxidant levels noted
proposed theories regarding preeclampsia
endothelial cell injury immune rejection of the placenta compromised placental perfusion imbalance bet. prostacyclin & thromboxane decreased glomerular filtration rate w/ retention of salt & H2O decreased intravascular vol. increased CNS irritability disseminated intravascular coagulation uterine m. stretch (ischemia) dietary factors, including vit. def. genetics air pollution obesity unfamiliar sperm theory thyroid dysfunction
evaluation of preeclampsia
detailed H&P- hx of HTN, previous preeclampsia
review of OB records if applicable
BP (tends to decline 2nd trimester)
wt- rapid wt gain (2 lbs/wk)
edema
DTRs- hyperreflexia or clonus at ankle worrisome
S&S’s of preeclampsia
visual disturbances severe/persistant HA RUQ pain hx of LOC/seizures dizziness
edema in preeclampsia
unresponsive to rest in supine position esp. in upper extremities, sacral egion & face
evaluation of the mother
CBC, esp. Hct platelet count- thrombocytopenia coag profile (PT, PTT)- coagulopathy LFTs- hepatocellular dysfunction SCr- decreased renal function uric acid 24 hr urine CrCl total urinary protein
Hct in preeclampsia
Hct signals worsening vasoconstriction & intravascular volume or hemolysis
lab studies of fetus
ULS for fetal wt, growth, amniotic fluid vol.
NST &/or biophysical profile- indirect assessment of placental status
Biophysical profile (BPP)
BPP has 5 components: 4 ULS assessments & a nonstress test (NST). The NST evaluates fetal HR & response to fetal mvnt. The 5 discrete biophysical variables:
- fetal mvnt
- fetal tone
- fetal breathing
- amniotic fluid volume
- fetal HR
NST/ Reactive FHR
nml= at least 2 accelerations in 30 min abnml= <2 accel. to satisfy the test in 30 min
ULS: fetal breathing mvnt
nml= at least 1 episode of breathing that lasts >30 seconds or >20s in 30 mins
abnml: none or < than 30s or 20s
ULS: fetal activity/ gross body mvnts
@ least 2 movnts of the torso or limbs
abnml: < 3 or 2 mvnts
ULS: fetal muscle tone
@ least 1 episode of active bendign & straightening of the limb/trunk
abnml: no mvnts or mvnts slow & incomplete
ULS: qualitative AFV/AFI
@ least 1 vertical pocket > 2cm or more in the vertical axis
abnml: largest vertical pocket </= 2 cm
BPP <2
labor induction
BPP 4
labor induction if gestational age >32 wks, repeating test same day if < 32 wks, then delivery if BPP <6
BPP 6
labor induction if >36 wks if favorable cervix & nml AFI, repeating test in 24 hrs if 6
BPP 8
labor induction if presence of oligohydramnios
BPP is not usually performed before what?
the 2nd half of a pregnancy, since fetal breathing mvnts do not occur in the 1st half
the presence of these biophysical variables implies absence of significant what?
CNS hypoxemia/acidemia @ the time of testing
a compromised fetus typically exhibits what?
loss of accelerations of the fetal heart rate (FHR)
decreased body mvnts & breathing
hypotonia
decreased amniotic fluid volume
mgnt of chronic HTN
goal: balance the mngt of both fetus & mother & to optimize outcome for mom & baby
- close monitoring of maternal BP
- watching for superimposition of preeclampsia/eclampsia
- following fetus for appropriate growth & fetal well being
- antiHTN meds if SBP is 150-160 or DBP 100-110
- purpose of med to to reduce likelihood of maternal stroke
mgnt of preeclampsia
care is individualized
mainstay of mgnt is rest & freq. monitoring of mother & fetus
2x weekly NST, BPP or both
ULS 1 3 wks for fetal growth & amniotic fluid assessment
daily kick counts
hospitalized initially for new onset
mgnt of severe preeclampsia
-best in tertiary care setting
-daily lab tests & fetal surveillance
-antiHTN therapy if repeated SBP > 160 or DBP > 105-110
-stabilize w/ magnesium sulfate
delivery via either induction or c-section
what type of BP med is given in severe preeclampsia
hydralazine
how is hydralazine given
in 5-10 mg incements until acceptable BP response
10-15 min response time is usual
goal of therapy is to reduce DBP to 90-100
further reduction may impair uterine blood flow
stabilizing w/ magnesium sulfate
used to prevent & tx eclamptic seizures
IM/IV 4-6 mg/dL
caution of toxic consequences
freq. eval of pts patellar reflexes & respirations
maint. of urine output of at least 25 mL/hr will avoid accum. in kidneys
reversal of effects done w/ shlow IV of 10% calcium gluconate, along w/ O2 supplementation
delivery by either induction or c-section
stabilize pt then focus on delivery of baby
closely monitor blood loss
obverse for min 24 hrs post delivery
further admin of Mg2+ sulfate
seizures can occur pre, during, post delivery
mngt of eclampsia
seizure life-threatening to both mother & fetus
maternal risks include: ms injury, hypoxia, aspiration
-insert padded tongue blade, restrain gently PRN, maintain adequate airway, gain IV access.
usu. self limited
tx directed to initiation of Mg2+ sulfate to prevent further seizures
if pt already receiving Mg2+ sulfate, an additional_________can be given slowly
2 g
get blood level
transient uterine hyperactivity for approx. 15 min associated w/ what?
fetal heart changes: bradycardia, decreased variability & late decelerations
usu. self limited
not dangerous unless > 20 min
delivery during this time unnecessary & should be avoided
place foley cath to monitor urine output
HELLP syndrome
Hemolytic anemia
Elevated Liver enzymes
Low Platelet count
considered a variant of preeclampsia
the findings of HELLP syndrome, a multisystem dz, attributed to?
abnormal vascular tone
vasospasm
coagulation defects
when does HELLP syndrome generally present?
3rd trimester
can occur < 27 wks
presents antepartum (69%), postpartum (31%)
postpartum onset
typically w/in 1st 48 hrs after delivery
may not become apparent for as long as 7 days after
pts usually multiparous
BP usually lower than preeclamptic pts
HELLP syndrome symptoms
may be vague n/v viral like syndrome generalized malaise epigastric pain HA early dx is critical- any 3rd trimester woman coming in w/ viral like sx's should be evaluated w/ CBC, LFTs
PE for HELLP syndrome pt
can reveal RUQ pain & tenderness
(rupture of liver capsule= hematomoa)
usually no proteinuria
labs in HELLP syndrome
CBC
CMP
coag studies
fibrin degredation products
tx done in high-risk OB center
Tx of HELLP syndrome
cardiovascular stabilization
correction of coagulation abnormalities & delivery
DIC (disseminated intravascular coagulation) occurs in 20% of HELLP pts
platelet perfusion indicated if platelet count < 20,000/mm3
may be advisable to perfuse when platelet count <50,000 before c-section
prophylactic transfusion of platelets at delivery does not reduce the incidence of what?
postpartum hemorrhage or hasten normalization of the platelet count
pts w/ DIC should be given what?
fressh frozen plasma & PRBCs
lab abnormalities in HELLP syndrome typically worsen when? begin to resolve when?
after delivery
3-4 days postpartum
HELLP syndrome summary
tx= prompt delivery Mg2+ sulfate- decreases risk of seizures blood transfusions- anemia DIC- fresh frozen plasma AntiHTN- labetalol, hydralazin, nefedipine
what does amniotic fluid protects against what
infxn
fetal trauma
umbilical cord compression
amniotic fluid has a pH of
7.5
approx. how much amniotic fluid at 20 ?wks? 28 wks?
400mL
800mL (plateaus here)
amniotic fluid allows for fetal movement & fetal breathing, which permits what?
fetal lung, chest & skeletal development
cushioning
prevents heat loss
polyhydramnios AFI (amniotic fluid index) >20 cm assoc. w/ what?
Down’s/Edwards
GDM
oligohydramnios AFI <5 cm assoc. w/ what?
UT abnormalities (bilateral renal agenesis- Potter's syndrome) maternal dehydration
PROM (premature rupture of membranes) overview
PROM is the rupture of chorioamniotic membranes BEFORE onset of labor
occurs in ~12% of pregnancies
assoc. w/ about 8% of term pregnancies
generally followed by onset of labor w/in 24 hrs
major complication of PROM
intrauterine infxn
cord prolapse, compression
fetal malpresentation
prolonged PROM defined as
> 18 hrs before onset of labor
consequence of PROM depends on what?
gestational age @ time of occurrence
can spontaneously heal
term PROM
PROM occurring >/= 37 wks
preterm PROM (PPROM)
PROM that occurs before 37 wks
what is the leading cause of neonatal morbidity & mortality?
PPROM
assoc. w/ 30-40% of preterm deliveries, making it the leading cause of preterm delivery
suggested etiology of PROM
STIs & other lower genital tract conditions (i.e. BV)
subclinical intraamniotic infxn may contribute to PROM
risk factors for PROM
smoking during pregnancy prior PROM short cervical length prior preterm delivery polyhydraminos multiple gestations bleeding in early pregnancy (threatened abortion)
Dx of PROM basics
-fluid passing thru vagina must be presumed to be amniotic fluid UNTIL proven otherwise
-pt will usually describe “gush” of fluid/ give hx of steady leakage of small amts of fluid
VS, abdominal exam
AVOID DIGITAL EXAM!!!! or keep to a min d/t risk of infxn
PROM Dx exams
sterile speculum exam
nitrazine test
fern test
ULS
sterile speculum exam
ontain cervical/ vaginal cultures for N. gonorrhoeae, B-hemolytic strep, C. trachomatis
cervix visualized for degree of dilation & free flowing amniotic fluid
fluid obtained for nitrazine &/or fern testing
Nitrazine test
-uses pH to distinguish amniotic fluid from urine & vaginal secretions
-amniotic fluid alkaline w/ pH >7.1
vaginal secretions pH 4.5 to 6.0
urine pH </= 6.0
sample of fluid obtained from vagina during speculum exam is placed on nitrazine paper
if pH is 7.1-7.3, paper = blue
cervical mucus, blood, semen, vaginitis are possible causes of false + results
fern test
amniotic fluid placed on slide & allowed to dry looks like a fern
cervical mucus usually does not fern but when it does it is a thick pattern w/ less branching
ULS for PROM
helpful in eval the possibility of rupture of membranes
looking for less than expected amt of fluid around fetus, then ddx of oligohydraminos is considered
labor & infxn less likely when adequate vol. of amniotic fluid remains w/ in uterus– 800cc @ 34 wks, 600 cc at term
also helpful w/ gestational age
mngnt of term PROM
90% of pts will experience spontaneous labor w/in 24 hrs
waiting for onset of spontaneous labor for 12-24 hrs reasonable unless presence of risk factors (GBS status, vaginal infxn, multiple deigital pelvic exams)
serial eval for devlop. of intrauterine infxn
induction of labor at any time after PROM considered appropriate
mngt of PPROM- latency period inversely related to gestational age
28 wks- term &24-28 wks
28 wks- term: 50% in labor w/in 24 hrs, 80% w/in 1 wk
24-28 wks: 50% in labor w/in 1 wk
amniocentesis- fetal LU maturity, eval for intra-amniotic infxn
suspicion of uterine infxn- delivery ASAP, regardless of gestational age
PPROM mgnt <24 wks
pt counseling regarding outcomes
expectant mngt or induction of labor
group B strep prophylaxis not recommended
Abx (data incomplete on prolonging latency)
PPROM mgnt 24 wks to 31 completed wks
expectant mgnt group B step prophylaxis recommended single-course corticosteroid use rec. Tocolytics- no consensus abx recommended to prolong latency if no CI
PPROM mgnt 23 wks- 33 completed wks
expectant mngt, unless fetal pulmonary maturity documented
group B strep prophylaxis recommended
corticosteroids- no consensus, but some experts recommend
Abx recommended to prolong latency, if no CI
PPROM mgnt 34-36 completed wks
same as for term
PPROM before 20-22 wks
risk of prematurity & infxn
additional risks 2/2 prolonged oligohydraminos: pulmonary hypoplasia, skeletal malformations, possible permanent deformities
these pts should be counseled regarding impact of immediate delivery & potential risks & benefits of expectant mngt
usually managed expectantly until viability
