Flashcards in CNM Random 2013 Deck (122)
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1
term
37 0/7 - 41 6/7 (or 42 0/7 ?) weeks
2
preterm
32 0/7 - 36 6/7 wks
3
very preterm
28 0/7 - 31 6/7 wks
4
extremely preterm
23 0/7 - 27 6/7 wks
5
Dx of preterm labor
regular uterine contractions
cervical change
cervix 2cm or greater and/or 80% or greater effaced by U/S
6
Etiology of PTL: pregnancy factors
infection (ex: pyelonephritis)
uterine bleeding (ex: abruption)
multiple pregnancy & hydramnios
uterine abnormalities (Asherman's syndrome)
incompetent cervix
7
Etiology of PTL: epidemiologic factors
race (AA)
maternal age (younger)
socio-economic status (unmarried, low SES)
working
smoking
psychological factors (stress, anxiety)
previous OB hx
nutritional status
???unknown causes
8
regarding PTL: an "injury" or inflammation (ischemic, infectious, traumatic, ?allergic) do what?
increase cytokine production that elicit production of prostaglandins
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regarding PTL: prostaglandins do what?
stimulate myometrial contractions and may initiate release of protease that can injure the membranes and decidua
10
interactive risk factors
intensity and duration of insult, gestational age, nutritional status, immune function may affect risk of PTB
11
s/s of PTL
change in Braxton Hicks
abdominal cramping
menstrual-like cramps
low back pain
intermittent pelvic pressure
change in character or amount of vaginal discharge
+ffn
short cervical length
12
fFN
glycoprotein normally found in fetal membranes and decidua.
found in cervicovaginal fluid BEFORE 16-18 wks.
NOT USUALLY PRESENT 22-37 weeks!!!
13
negative fFN in a woman with preterm contractions
99% accurate for predicting no PTB in next 7 days
14
transvaginal sonographic cervical length
effective marker for predicting PTB, particularly in women symptomatic of preterm labor or at a higher risk of spontaneous PTB.
The greater the degree of funnelling measured, the more accurate sonography was in predicting PTB
15
guidelines for dx of PTL
s/s of PTL
Monitoring for fetal well-being and uterine activity
Transabdominal U/S for placental location, amniotic fluid volume, fetal presentation, EFW
Sterile spec
digital exam
16
sterile speculum exam in r/o PTL
fibronectin swab, GC/CT, fern, pooled fluid, cultured for GBS
17
Dx of BV
presence of clue cells
vaginal pH >4.5
profuse white discharge
fishy odor when d/c exposed to potassium hydroxide
18
sequelae of BV
1..5-3 fold increase in PTB (unsure why)
Black women have BV 3x more than white women
19
Tx of PTL: criteria for use of tocolytics
20-34 wks
contractions have effects on cervix
regular contractions
20
tocolytic choices in PTL
beta agonists
magnesium sulfate
anti-prostaglandins
Ca channel agonists
oxytocin antagonists
progesterone
21
beta-adrenergic agonists in PTL
B1 receptors: heart, intestines
B2 receptors: myometrium, blood vessels, bronchioles
Terbutaline (sq, may be given IV)
S/E: maternal tachycardia, N/V, HA, dyspnea, nervousness, anxiety, fetal tachycardia, neo hypotension, hyperglycemia with consequent hypOglycemia, may increase incidence of intraventricular hemorrhage
22
Magnesium sulfate in PTL
Diminishes excitability of muscle fibers and relaxes uterus, alters myometrial contractility
S/E: maternal sweating, drowsiness, depressed reflexes, hypotension, respiratory arrest, depressed cardiac function, neonatal hypotonia, lethargy, weakness, low APGAR score
23
Prostaglandin synthase inhibitors in PTL
Block action of prostaglandin which are involved in myometrial contractility: Indomethacin (PO, PR)
-compared with beta-agonists, is more effective in delaying delivery by 48 hours and has fewer side effects
S/E: maternal N/V, heartburn, rare GI bleed, thrombocytopenia, increase BP in hypertensive women
-cannot be used for long-term management because it may produce closure of ductus arteriosus, necrotizing enterocolitis, intracranial hemorrhage
24
Ca channel blockers in PTL
Reduces Ca++ [ ] and inhibits contraction
Nifedipine
S/E: maybe maternal hypotension and decreased uteroplacental perfusion, HA, flushing
25
Progesterone in preventing PTL
17 alpha-hydroxyprogesterone acetate
Promising new tool to prevent PTB, for now restricted its use to previous unexplained spontaneous preterm birth
Reduction in the risk for PTB (<34 wks)
Reduction in LBW
26
Glucocorticoid rx in PTL
to accelerate lung maturation in fetus (<34 wks)
Effective in preventing RDS and neonatal mortality
A SINGLE course of steroids:
Betamethasone 12 mg IM, 2 doses q 24 hours -OR-
Dexamethasone 6 mg IM , 4 doses q 12 hours
Not sufficient evidence for repeated doses
27
Hydration in PTL
insufficient data to support hydration as a specific tx
Two studies did not show any advantage, even in the initial period after admission
Women with evidence of dehydration may benefit from this intervention
28
Psychologic factors with PTL/PTB
Stress (anxiety, perceived stress, psychological distress) assoc with increased risk of PTL/PTB
Stress stimulates HPA axis and increases production of cortisol and cytokines which have been correlated with PTL/PTB
Stress mgmt
29
PROM
after 37 weeks
ROM at least 1 hr before onset of labor
8% of pregnancies
50% deliver within 5 hours
95% deliver within 28 hours
If not in labor, proceed with induction
30