Repro IF: Preeclampsia, Fetal Surveillance, Amniotic Fluid, GDM Flashcards
What are the 2 main methods of Antepartum Fetal Surveillance?
Non-stress test (first-line after 32 weeks) Biophysical Profile (BPP); optional inclusion of NST, can do if nonreactive NST
NST measures what?
Noninvasive cardiotocography, measures FHR accelerations/decelerations in reaction to fetal movements over 20 min
What is a reactive (normal) NST?
2+ FHR accelerations peaking at 15+ bpm above baseline and lasting 15+ seconds
What is a nonreactive NST? Next steps?
<2 accelerations
1) Vibroacoustic stimulation then record for 20 more minutes (fetus may be sleeping)
2) If still non reactive –> BPP or contraction stress test
What is a contraction stress test
Administer oxytocin and measure FHR decelerations during contractions
What is the BPP? Timing?
After 28th week
30 minutes of monitoring
1) Tone (1+ episodes of extension-flexion)
2) Movement (3+ movements within 30 min)
3) Breathing (1+ episodes >30sec withing 30 min)
4) Amniotic fluid (SDP 2-8cm)
5) NST (optional)
Scoring of BPP?
+2 per normal item, 0 if abnormal
8+ = good
6 = unclear risk, repeat within 24 hours
4 or less –> delivery indicated if 32+ weeks (if <32 weeks, give antenatal steroids and monitor)
2 main ways of measuring amniotic fluid volume and normal values
Single deepest pocket (AKA deepest vertical pocket) = 2-8 cm
Amniotic Fluid Index = 5-25 cm
How is amniotic fluid index measured?
Sum of amniotic fluid pockets in 4 uterine quadrants
Limb complication of early oligohydramnios
Contractures
Symptom of oligohydramnios
Decreased fetal movement
If AFI <5 (oligohydramnios), what further diagnostics may be done? (3)
1) Anatomical U/S
2) Amnio/karyotyping offered if aneuploidy possible
3) Doppler U/S of umbilical artery if indicated
If olighydramnios is uncomplicated, when should delivery be done?
36-37+6 wks
usually C-section because fetus may not tolerate labour
If AFI >25, what further diagnostics? (polyhydramnios)
4
1) Anatomic U/S
2) Maternal glucose tolerance test
3) Maternal serology for infection
4) Amniocentesis/fetal karyotype for hereditary disorders
Deliver when for polyhydramnios?
39 weeks
The interval between PROM and onset of spontaneous labor (latent period) and delivery varies inversely with gestational age. At term, > 90% of women with PROM begin labor within __ hours; at 32 to 34 weeks, mean latency period is about ____.
24hrs
4 days
Prolonged rupture of membranes is defined as
Rupture –> delivery > 18 hours
3 possible consequences of fetal exposure to vaginal flora during PPROM
Endometritis
Chorioamnionitis
Fetal infection
Placental abruption (neutrophils degrade placenta)
When is magnesium sulfate administered in preterm labour/PPROM?
24-31’6 weeks to reduce intraventricular hemorrhage/CP
Also has tocolytic properties
Can be administered up to 48 hours (?)
What are 2 first-line tocolytics? WHat is a 3rd tocolytic that is also commonly administered but less effective?
1) Indomethacin (NSAID 24-32 wks)
2) Nifedipine (CCB, 32-34 wks)
3) Magnesium sulfate (neuroprotective, <32 weeks)
Why is indomethacin contraindicated after 32 weeks?
Reduction in PGs can lead to premature closure of ductus arteriosus
Antibiotics used in preterm labour if GBS status unknown
Penicillin or ampicillin
if allergy w/ low anaphylaxis risk –> cefazolin (1st gen IV cephalosporin)
If high risk of anaphylaxis –> clindamycin if anovaginal cultures show susceptibility, vancomycin if unknown or resistant
2 steroid regimes for <34 weeks
Steroid regime for 34-36’6?
1) Betamethasone 2X (24 hrs apart)
2) Dexamethasone 4X (12 hrs apart)
ALPS = antenatal late preterm steroids = 1 dose betamethasone
What are “rescue” steroids?
Additional steroids given if >14 days since last course and delivery again expected within 7 days (as it was the first time)
____ exam is done to verify PROM rather than _____. Why?
Sterile speculum rather than bimanual (unless delivery imminent) because infection risk
Steroids for fetal lung maturity are administered during PPROM/Preterm labour at what weeks?
24-33’6 (ALP from 34-36’6)
What are 6 main hypertensive pregnancy disorders?
1) Gestational Htn: sys >140 or dias >90; onset 20+ weeks
2) Chronic Htn: diagnosed <20 weeks
3) Preeclampsia: gestational htn w/ proteinuria or end-organ dysfunction; may progress to eclampsia (seizures/coma)
4) Superimposed Preeclampsia (on top of chronic)
5) HELLP Syndrome: Hemolysis, Elevated Liver enzymes, Low Platelets
6) Postpartum Htn: persisting <12 weeks after delivery (if longer, investigate for secondary cause)
HELLP syndrome is often classified as a severe form of preeclampsia. Why is this controversial?
Because 15% of causes do not have htn or proteinuria!
Describe the basic pathophysiology of gestational hypertensive disorders
Multifactorial placental hypoperfusion (spiral arteries don’t expand properly; arterial hypertension + systemic vasoconstriction; systemic endothelial dysfunction)
Factors are released to increase bloodflow to fetus by increasing maternal BP
Endothelial dysfunction + placental release of factors also –> microthrombosis
Pathophys of eclampsia
Htn-induced vasoconstriction + endothelial damage –> disruption of cerebral microcirculation (microthrombi) –> CNS vasospasms
Hypertensive disorders can have systemic effects on what organs?
Kidney (preeclampsia, HELLP) Lungs (too much afterload --> pulmonary edema/RD; severe preecl & HELLP) Liver (swells; HELLP, severe preecl) CNS (eclampsia) Blood (DIC; HELLPS, severe preecl)
90% of preeclampsia has onset when?
> 34 wks
