Parturition - Preterm Birth Flashcards
Preterm birth is
Preterm < 37
Very preterm < 32
Which factors determine survival for a preterm baby?
Gestation and birth weight
Outcomes are good for a preterm baby at ___ weeks and ___g
28-29 weeks
1250 g
What are four factors that might cause premature birth?
- Stress
- Bleeding
- Infection
- XS stretch
The earlier the labour occurs the more likely it is to have an ____ aetiology
Infectious/inflammatory
Why might cervical damage lead to preterm labour?
Weakens the bacteriostatic barrier (operculum)
Infection in preterm labour is though to be ascending/descending
Ascending
What are some potential consequences of preterm labour?
- Immature foetus
- Malpresentation
- Maternal comorbodities
- Complicated C sections
- Recurrence risk
- Poor outcomes
What are the two main causes of iatrogenic preterm birth?
- Maternal disease (preeclampsia)
- Foetal health (IUGR)
What is eclampsia?
A grand-mal convulsion due to endovascular inflammation
What is the highest risk factor for PTB?
Previous PTB
What are non-modifiable risk factors for PTB?
- Maternal age
- Obstetric history
- SES
- Race
What are modifiable risk factors for PTB?
- Smoking
- Need for cervical surgery
- Reproductive technologies
- No prenatal care
Shorter/longer cervix is associated with higher risk of PTB
Shorter
What other markers have been suggested for PTB risk screening?
- Serum biomarkers
- Cervicovaginal fluids
- Cervical length
- Uterine activity
Foetal fibronectin is a biologial glue that sits between the ___ and ___
Decidua and chorion
After __ weeks pregnancy there is not supposed to be any fibronectin in the vagina
20
Of the women with a negative fibronectin test, ___% don’t deliver in 7-10 days
99.5
What is the main drug used in tocolysis (suppression of labour)?
Nifedipine (Ca Channel blocker)
Which drugs were previously used to suppress premature labour?
- B2 agonist (salbutamol)
- PG agonist (idomethacin)
Which antenatal corticosteroid is used to prevent respiratory distress syndrome?
Betamethasone
Which drug is administered to premature babies for neuroprotection?
MgSO4
MgSO4 is administered in babies under __ weeks ~ ___h before birth
30 weeks
6h before birth
When is progesterone gel most effective in suppressing labour?
- Cx length 10-20mm
- 19-23 wks
- Singletons
- Prior STB
