Premature Labor PROM Flashcards
Definition of Pre-term birth
Birth < 37 weeks AOG
Classifications of Pre-term birth
Extremely Preterm: < 28 weeks
Very Preterm: 28 to 31 6/7 weeks
Moderate Preterm: 32 to 33 6/7 weeks
Late Preterm: 34 to 26 6/7 weeks
Pathways of Pre-term Birth
- Activation of HPA Axis
- Infection and Inflammation
- Decidual hemorrhage
- Pathological uterine distention
Pathology behind maternal stress induced activation of HPA Axis
Stress causes increased cortisol –> Negative feedback to Hypothalamus –> CRH Production by Placenta –> More cortisol production –> More Estrogen and Prostaglandin production –> Cervical contractions
Pathology behind fetal stress induced activation of the HPA Axis
Uteroplacental insufficiency –> Release of ACTH –> DHEAS activation –> Estrogen increase
Pathology behind inflammation induced Pre-term labor
Increase in cytokines (TNF-a, IL-8) –> Increase in Uterotonins (PGs, Endothelin) –> Increase in Proteases (MMPs) –> Apoptosis –> Membrane rupture and Cervical ripening
Pathology behind Decidual hemorrhage induced Pre-term labor
Decidual hemorrhage –> Release of clotting factors III, VIIa, Xa –> Uterine contraction to prevent bleeding
Pathology behind Uterine distention induced Pre-term labor
Fetal Macrosomia
Multifetal gestation
Polyhydramnios
3 Circumstances in which Cervical cerclage may be performed
1) History-indicated Cerclage (≥ 3 prior preterm deliveries)
2) Ultrasound indicated Cerclage (Cervix < 24mm)
3) Rescue Cerclage
Definition of a Short Cervix that would also indicate Cervical Cerclage
Cervix < 24mm before 24 weeks AOG
An intercellular adhesion molecule seen between the fetal and maternal membranes; a finding in cervicovaginal secretions would indicate separation of membranes
Fetal Fibronectin
A negative Fetal Fibronectin test provides a 99% assurance that the woman will not deliver within the next ___ weeks.
2 weeks
Clinical symptoms of Preterm Labor (in the setting of < 37 weeks AOG)
> Persistent uterine contractions with pelvic pressure
Cramps/Backache
Vaginal discharge
Vaginal spotting
Leakage of fluid
Confirmed PTL definition
- AOG < 37 weeks
- ≥ 3cm Cervix dilation
- ≥ 80% Cervix effacement
- Symptoms of acute PTL
Antenatal Corticosteroids are recommended to be given for PTL starting ≥ ____ weeks
≥ 24 weeks
Fetal lungs reach a stage of development biologically responsive to ACS
Types of Antenatal corticosteroids given and their dosages
> Betamethasone (12mg/IM) Q24 for 2 doses
Dexamethasone (6mg/IM) Q12 for 4 doses
According to the local PSMFM guidelines, Timely administration of Antenatal corticosteroids for PTL is between ___ to ___ weeks
26 to 34 weeks
ACS Should not be administered at 36 to 36 6/7 weeks due to what complications
Fetal Hypoglycemia
Medication given additionally for Neuroprotective effects on the fetus
Magnesium Sulfate
Dosage of MagSul
4g IV loading dose for 20 minutes, followed by 1g/hr for 24 hours
Indications for Antimicrobials in the setting of PTL
- Bacterial Vaginosis
- Trichomonas
- Chlamydia cervicitis
- Gonorrhea
- Asymptomatic Bacteriuria
Antimicrobials given for Bacterial Vaginosis
> Metronidazole 500mg BID for 7 days
OR
Clindamycin 300mg BID for 7 days
Antimicrobials given for Chlamydia Cervicitis
> Azithromycin 1g single dose
OR
Erythromycin 50mg QID for 7 days
Antimicrobials given for N. Gonorrhea
> Ceftriaxone 250mg IM single dose
OR
Cefixime 400mg Single dose
Antimicrobials given for Asymptomatic Bacteriuria
> Fosfomycin 3g granules single dose
OR
Nitrofurantoin 100mg TID for 7 days
Antimicrobials given for GBS
> Benzyl Penicillin G 5m units IV, then 2.5-3m units Q4 until delivery
Test done on cervicovaginal secretions to check pH
Nitrazine test
