MFM Flashcards
The biggest RF for PTL
Hx of spontaneous PTB, often occurs at the same GA or earlier
interventions to reduce PTL
- progesterone per vagina
- cerclage of cervix
- low dose asa
- removal of large fibroids
- ideally is 12-18m inter-pregnancy interval
- smoking cessation
- multifetal gestation
Causes of PTL
- Maternal stress
- Infection/inflammation
- Decidual Hemorrhage
- Pathologic Uterine Distention (Polyhydraminos, multiples)
True labour
Contractions that result in cervical change
Cervical change is defined as
dilation, effacement, softening, moving anterior
rate of cervival change important
Tocolytics are used for
Administration of a tocolytic rx can reduce the strength and frequency of uterine contraction
Tocolytic indications
- To try to reduce the strength/frequency of contractions.
- To delay/halt/prevent PTL
- To try to get to appropriate level of care for mother/fetus
- Used for 48hrs in Canada
Tocolytic medications
- Adalat (Nifedipine)
- indocid
- ventolin
- magnesum
- nitro patch
- terbutaline, ritodrine
Nifedipine (adalat)
used as a tocolytic for PTL (calcium channel blocker)
used in preeclampsia
evidence of benefit
less fetal harm
material s/s: n,v, hypotension, dizziness, h/a
you can use Nifedipine and magnesium together
Why use steroids in antenatal care?
Administration of antenatal corticosteroids to patients at risk for preterm birth reduces neonatal mortality when delivery occurs within 7 days help fetal lung develop
What steroids are given?
Betamethasone and dexamethasone
Chorioamnionitis definition
maternal fever >38 with tachycardia pulse signs of maternal sepsis
Tx: delivery and broad spectrum abx
Definition of preeclampsia
Resistant HTN with new/worsening proteinuria and adverse effects (H/A, Blurred vision, epigastric pain, IUGR, Oligo) after 20 weeks GA
Target organ damage in pre-eclampsia
maternal = eclampsia, ICH, Pulmonary edema, liver fetal = IUGR, oligo, abnormal doppler, abnormal EFM
criteria for blood pressure in preeclampsia
≥140/≥90 = HTN ≥160/≥110 = Severe HTN
eclampsia is
a grand mal seizure with pre-eclampsia
HELLP is
hemolysis elevated liver enzymes and low platelets. It represents a subtype of pre-eclampsia with severe features in which hemolysis, elevated liver enzyme and low platelets are the predominant features, rather than HTN or CNS/renal dysfunction.
Preeclampsia indications for delivery
- worsening maternal status:
- increasing bp
- HELLP syndrome
- eclampsia
- increasing serum cr
- abruption/DIC - Compromised Fetal status
- IUGR
- Abnormal Doppler
- oligohydramnios
Treat pre-eclampsia with
Nefidapine, then labetalol
Treat eclampsia with
4g of magnesium iv over 10-20 minutes
then 1g/hr for 24 hours
important Hormones associated with maternal physiology
- progesterone
- prostaglandins
- oxytocin
- estrogen
- relaxin/cytokines and para-thyrpod hormones
Factors inducing of labour
- fetus (HPA stress, cortisol)
- myometrial activation
- hormones
- membrane rupture
how does indocin (indomethacin) work and why is it used as a tocolytic
Indacin inhibits the production of arachnoidic acid, which inhibits prostagland synthesis (used as a tocolytic)
Benefits of oxytocin
○ Precursor produced in hypothalamus
○ Secreted from posterior pituitary in active labour
○ Oxytocin receptors are present on myometrium
§ Receptor increase near term
§ Receptors increased estradiol
§ Receptors down-regulated by progesterone
○ Oxytocin causes contractions by increasing intracellular calcium
Five P’s of labor
passage passenger power position psyche/partners
treatment for short cervix
• Progesterone
• Cerclage
~Pessary
Initial Assessment for <34 weeks gestation with symptoms of preterm labour
- Check gestational age
- Palpate contractions
- Sterile speculum exam:
a. Cultures
b. Rule out preterm ROM
c. Take FFN Swab
Perform digital assessment of CX
Tocolytic Therapy goals
- Delay delivery 24-48 hours if GA <34 weeks
- Antibiotics: prevention of neonatal group B strep sepsis
- Steroid therapy for prevention of neonatal RDS
- Transport to appropriate centre for higher level of care if required
Nifedipine MOA, dose and indications
MOA: calcium channel blocker
Dose: PTL = Loading dose of 10mg q 15 until contractions stop (4 doses max). Then XL dose
Indicated for: PTL, and for pre-eclampsia
Preterm labour treatments:
- Betamethasone (corticosteroid for lung/gut/neuro protection)
- Tocoyltic (nifedipine, Indocin for meds to work/transport)
- Abx (Group B strep)
- Magnesium for fetal neuroprotection
Consequences of PPROM
• Preterm delivery • Fetal pulmonary hypoplasia • Fetal skeletal maldevelopment • Ascending infection ○ Maternal sepsis ○ Neonatal sepsis Independent risk factor for cerebral palsy
PPROM dx
Ferning and pH <7
PPROM mgmt
• 24-34 weeks
• Ampicillin 2G IV q 6 h, erythromycin 250mg IV q6 h for 48hr
• Amoxicillin 250mg q 8h, erythromycin base 333mg q 8 hours for 5 days
• Single course of corticosteroids
• Monitor for signs of infection
• Monitor for signs for preterm labour
Deliver at 34-36 weeks, or when indicated
difference between abx for PPROM and PTL or someone who has Group B strep
- PPROM abx essentially are used to keep baby inside so corticosteroids can work
- PTL/GROUP B strep is to prevent baby from getting septic during delivery from mom who has a high risk or has group b
neonate risk of infection
• <37 weeks
• >18 hours PROM
• Intraamniotic infection
Previous affected neonate
labs in HELLP
• Hemolysis ○ Peripheral smear w/ schistocytes and burr cells ○ Bili >20mmol ○ Low LDH, Low heptaglobin ○ Severe anemia unrelated to blood loss • HELLP ○ Two x upper limit of normal Plts <100
severe preeclampsia
>160/110
**preeclampsia before 34 weeks **
protein 3g/24h
(spot urine, cr protein ratio 250g/mol)
