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
