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51 Cards in this Set
- Front
- Back
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What is the definition of preterm labor?
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labor (regular contractions with cervical change) before 37 weeks' gestation
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What is the definition of incompetent cervix?
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silent, painless dilation of the cervix
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What is the leading cause of fetal morbidity and mortality in the USA?
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preterm delivery
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what is the definition of a low birth weight (LBW) infant?
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one weighing less than 2500 g
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Prematurity places infants at higher risk for what complications?
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1. hyaline membrane disease (neonatal RDS)
2. intraventricular hemorrhage 3. sepsis 4. necrotizing enterocolitis |
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what is the mortality rate of infants born at the cusp of viability (~24 wks)?
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50%
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What are risk factors for preterm labor?
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1. PPROM
2. chroioamnionitis 3. multiple gestations 4. uterine anomalies (bicornuate uterus) 5. previous preterm delivery 6. maternal prepregnancy weight <50 kg 7. placental abruption 8. maternal disease including preeclampsia 9. infections 10. intra-abdominal surgery 11. low socioeconomic status |
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What drug is used to help prevent neonatal RDS?
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betamethasone (glucocorticoid) used prior to 34 wks' gestation
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what is the next step of management of a woman of 25 wks gestation who has no cervical change but is experiencing contractions?
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hydration (decreases production of ADH, which cross-reacts with oxytocin receptors)
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What are the 5 major classes of tocolytics?
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Beta-mimetics, MgSO4, calcium channel blockers, prostaglandin inhibitors, oxytocin antagonists
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Beta-mimetics as tocolytics: mechanism, efficacy, SE
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mechanism: increased cAMP sequesters Ca in SR
Efficacy: stops contractions for 24-48 hours beyond hydration and bed rest SE: tachycardia, HA, anxiety, PE |
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Magnesium Sulfate as a tocolytic: mechanism, efficacy, SE
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Mechanism: calcium antagonist and membrane stabilizer
Efficacy: similar to B-mimetics (24-48 hrs) SE: flushing, HA, fatigue, diplopia |
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What are signs of magnesium toxicity and at what levels do they occur?
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>10 mg/dL, see hyperreflexia
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what are the complications of using prostaglandin inhibitors (indomethacin) for tocolysis?
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fetal complications including premature constriction of ductus arteriosus, pulmonary hypertension, oligohydramnios secondary to renal failure
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what is the frequency of preterm deliveries in the US?
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11% in 2003
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how long before delivery must the rupture of membranes occur to be considered prolonged rupture of membranes?
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18 hours
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what are the major complications of prolonged PPROM?
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increased risk of chorioamnionitis, abruption and cord prolapse
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how is a diagnosis of ROM made?
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history of vaginal leaking, pooling on speculum exam, positive nitrazine and fern tests, ultrasound, or amnio dye test.
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How does one treat PPROM?
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Weigh the balance of risk of infection and fetal immaturity. Give ampicillin with or without erythromycin as prophylaxis. Deliver when prudent.
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What are the factors involved in cephalopelvic disproportion?
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3 P's: pelvis, passenger, power
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What are the four types of maternal pelvises?
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gynecoid, android, anthropoid and platypelloid
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What is the obstetric conjugate?
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the distance between teh sacral promontory and the midpoint of the symphysis pubis (the shortest anteroposterior diameter of the pelvic inlet).
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How many bones comprise the fetal vault?
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5: 2 frontal, 2 parietal and 1 occipital
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what is the average size of the maternal pelvic outlet (anteroposterior diameter)?
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9.5-11.5 cm
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What is asynclitism?
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occurs when the sagittal suture of the presenting fetus is not located midline in the pelvic outlet.
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What are factors associated with breech delivery?
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1. previous breech delivery
2. uterine anomalies 3. polyhydramnios 4. oligohydramnios 5. multiple gestations 6. PPROM 7. hydrocephalus 8. anencephalus |
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What is a frank breech presentation?
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flexed hips and extended knees - feet near fetal head
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What is a complete breech?
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flexed hips and flexed knees - at least one foot is near the breech
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What is an incomplete or footlong breech presentation?
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one or more of the hips are extended so that the foot or knee lies below the breech in the birth canal
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How is the diagnosis of breech made?
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Leopold maneuvers, vaginal exam or Ultrasound
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What are three treatment options for breech presentation?
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external version of the breech, trial of breech vaginal delivery, and elective cesarean section
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What factors would indicate cesarean delivery to be the favorable mode in a breech presentation?
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EFW > 3800 g, incomplete breech presentation, nulliparity
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What position of a face presentation can be delivered vaginally?
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mentum anterior (mentum posterior or transverse mentum requires that the fetus rotate before delivery)
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Why is augmentation of labor rarely in face presentation?
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pressure on the face may lead to edema
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how does one deliver a persistent OT presentation?
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manually rotate or use vacuum delivery. If unable to deliver use Cesarean.
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What is the definition of a prolonged deceleration?
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FHT < 120 for longer than 2 minutes
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What conditions are associated with prolonged decelerations?
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1. placental abruption
2. cord prolapse 3. tetanic contraction 4. uterine rupture 5. pulmonary embolus 6. amniotic fluid embolus 7. seizure |
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Pre-placental etiologies of FHR decelerations?
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1. seizure
2. AFE 3. PE 4. MI 5. Respiratory failure 6. recent epidural or spinal placement |
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Placental etiologies of FHR deceleration?
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1. abruption
2. placental infarction 3. previa |
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post-placental etiologies of FHR deceleration?
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1. cord compression
2. cord prolapse 3. rupture of fetal vessel |
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What are the maneuvers used to deliver shoulder dystocia?
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1. McRoberts maneuver
2. Suprapubic pressure delivered at an oblique angle 3. Rubin maneuver 4. Wood corkscrew maneuver 5. Delivery of the posterior arm/shoulder 6. fracture of the fetus's clavicle 7. Symphysiotomy 8. Zavanelli maneuver |
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What are the risk factors for fetal shoulder dystocia?
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1. fetal macrosomia
2. preconceptional and gestational diabetes 3. previous shoulder dystocia 4. maternal obesity 5. postterm pregnancy 6. prolonged second stage of labor 7. operative vaginal delivery |
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how often does uterine rupture occur in patients with no previous uterine scars? patients with prior uterine scars?
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1 in 10000 or 20000 with no prior scars
0.5% to 1.0% with prior scar |
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What are associated complications in patients with uterine rupture with no prior uterine scars?
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uterine fibroids, uterine malformations, obstructed labor, use of uterotonic agents (oxytocin and prostaglandins)
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what can be seen on physical exam in a patient with uterine rupture?
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fetus palpable extrauterine, vaginal bleeding, fetal presenting part is suddenly much higher than expected
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what are the symptoms of uterine rupture?
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Fetal bradycardia with sudden "popping" sensation or sudden abdominal pain
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What is the threshold for maternal hypotension in a pregnant woman?
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BP below 80/40
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What are common etiologies of maternal hypotension?
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1. vasovagal events
2. regional anesthesia 3. overtreatment with antihypertensives 4. hemorrhage 5. anaphylaxis 6. amniotic fluid embolus (AFE) |
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What are the mainstays of treatment for maternal hypotension?
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aggressive IV hydration and adrenergic medications to clamp down peripheral vasculature. Benadryl and epinephrine for anaphylaxis
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how does one differentiate a seizure from tonic-clonic contractions of a vasovagal response?
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a postictal period after the event and a head CT when save for patient to leave the floor.
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What are the first steps of management in patients with seizures in pregnancy?
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Assess and establish airway and vital signs
Assess FHR or fetal status Bolus MgSO4 |
