Preterm birth

Question 1

There is increasing risk of mortality and handicap the the more preterm you are born.

Answer 1

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Question 2

There is increasing risk of mortality and handicap the the more preterm you are born.

Answer 2

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Question 3

Draw the mechanisms for spontaneous pre-term births.

Answer 3

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Question 4

What are main triggers for pre term birth

Answer 4

1) Inc. uterine stretch
- From twins, or polyhydramnios
- Causes expression of genes (CAP) and cytokines involved with parturition.

2) Foetal endocrine activation

3) Intrauterine bleeding (most potent)
- Can cause inflammatory response (cervical ripening) and membrane rupture.

4) Infection - inflammation
- PG and cytokines which induce cervical ripening and parturition

5) Cervical changes

Question 5

Main primary cause of primary pre term cervical changes

Answer 5

Infection/inflammation causing erosion of highly conccentrated collagen ECM

Also

Question 6

Common problems of pre term birth

Answer 6

Immature foetus 
Maternal co-morbidities  
Often delivered in breech 
Complicated C-sections
Risk of recurrence

Question 7

Organ of post natal gas exchange

Answer 7

Lung alveoli

Question 8

Main cause for death in pre term neo nates

Answer 8

Lung viability:
Early on was respiratory distress synrome
Later Bronchopulmonary dysplasia

Question 9

Iatrogenic reasons for pre term birth

Answer 9

Pre eclampsia

Foetal health - FGR

Question 10

Major risk factors for pre term birth

Answer 10

MODIFIABLE

1) Smoking
2) No prenatal care
3) Cervical surgery

NON-MODIFIABLE

1) History, parity? prior ptb?
2) Maternal age
3) Race
4) SES

Question 11

How to test for threatened pre term birth

Answer 11

1) foetal fibronectin
- Acts as a glue between chorion and decidua
- High early and late in pregnancy
- Negligible levels during (22-25 wks)
Therefore we measure levels during this period
If positive (fFN present) then 30% chance of delivery in next 7-10 days
If negative (fFN not present) then 99.5% chance of no delivery.

Question 12

Treatment for pre term babies

Answer 12

1) Tocolytics - Nifedipine - suppress labour
2) Corticosteroids - Betamethasone - Aid in lung maturity by stimulating surfactant production. Greatly reduces risk of respiratory distress syndrome.
3) MgSO4 - Magnesium sulphate is given to mothers IV <30 wks gestation. It greatly reduces the risk of neurological pathologies such as cerebal palsy.

Question 13

Single highest risk factor for pre term birth

Answer 13

Short cervical length

Question 14

What can be used to prevent sPTB?

Answer 14

Progesterone! Despite there being high levels in serum throughout pregnancy, it still reduces the risk of sPTB by 45% if given via progesterone gel at around 19-23 wks.