Preterm Labour Flashcards
Explain the staging and treatment for the different wks of preterm labour.
Late > 34wks deliver Steroid + tocolytics + magnesium sulphate Moderate 32-33 Very 28-32 Extreme <28wks
How could you predict a preterm labour?
1) Risk factors- previous preterm, multiple, cervical abnormal
2) Cervical assessment
3) Infection screen
4) Foetal fibronectin- shouldnt be present between 20-32wks
What are some risk factors for preterm labour?
Previous preterm
Multiple births
cervical abnormalities/ surgery e.g. LETX
Uterine abnormalities
What is foetal fibronectin?
A protein which connects the foetal and maternal membranes. It should not be found between wk 20-34.
Describe the primary prevention for preterm birth.
Smoking prevention
Single embryo transfer- decreases mutliple births
Describe the secondary prevention for preterm birth.
For those at high risk: Cervical length screening Cervical cerclage/ pessary Progesterone Abx for subclinical infections as small percentage will develop.
Describe the tertiary prevention for preterm birth.
For those in preterm labour-
1) Tocolytics- delay delivery e.g. nifedipine
2) Antenatal steroids
3) Magnesium sulphate - decreases risk of cerebral palsy
Describe how infection can cause preterm birth.
20-40% have some evidence of infection
Maternal- IL1 and TNFalpha –> increased prostagladins and contration, cervical rippening
Foetal stress- CRH –> cortisol
What causes cervical insufficiency?
Premature rippening - 50% have some evidence of inflammation.
LLETZ- for cervical cancer
congential
What causes overdistension of the uterus?
multiple pregnancy
Polyhydramnious
What causes ischemia to the foetus?
Placental abruption, placental lesions cause thrombosis of the spiral arteries.
The foetal membranes then activate there own RAAS- > angiotensin II –> myometrial contraction.
