CNM Random 2013 Flashcards
term
37 0/7 - 41 6/7 (or 42 0/7 ?) weeks
preterm
32 0/7 - 36 6/7 wks
very preterm
28 0/7 - 31 6/7 wks
extremely preterm
23 0/7 - 27 6/7 wks
Dx of preterm labor
regular uterine contractions
cervical change
cervix 2cm or greater and/or 80% or greater effaced by U/S
Etiology of PTL: pregnancy factors
infection (ex: pyelonephritis) uterine bleeding (ex: abruption) multiple pregnancy & hydramnios uterine abnormalities (Asherman's syndrome) incompetent cervix
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
regarding PTL: an “injury” or inflammation (ischemic, infectious, traumatic, ?allergic) do what?
increase cytokine production that elicit production of prostaglandins
regarding PTL: prostaglandins do what?
stimulate myometrial contractions and may initiate release of protease that can injure the membranes and decidua
interactive risk factors
intensity and duration of insult, gestational age, nutritional status, immune function may affect risk of PTB
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
fFN
glycoprotein normally found in fetal membranes and decidua.
found in cervicovaginal fluid BEFORE 16-18 wks.
NOT USUALLY PRESENT 22-37 weeks!!!
negative fFN in a woman with preterm contractions
99% accurate for predicting no PTB in next 7 days
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
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
sterile speculum exam in r/o PTL
fibronectin swab, GC/CT, fern, pooled fluid, cultured for GBS
Dx of BV
presence of clue cells
vaginal pH >4.5
profuse white discharge
fishy odor when d/c exposed to potassium hydroxide
sequelae of BV
1..5-3 fold increase in PTB (unsure why)
Black women have BV 3x more than white women
Tx of PTL: criteria for use of tocolytics
20-34 wks
contractions have effects on cervix
regular contractions
tocolytic choices in PTL
beta agonists magnesium sulfate anti-prostaglandins Ca channel agonists oxytocin antagonists progesterone
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
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
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
Ca channel blockers in PTL
Reduces Ca++ [ ] and inhibits contraction
Nifedipine
S/E: maybe maternal hypotension and decreased uteroplacental perfusion, HA, flushing