8: Pre term birth

Question 1

What is pre term birth?

Answer 1

Onset of labour before completion of 37 weeks gestation (regular contractions and cervical dilatation of >= 3cm)

Question 2

Contributions of iatrogenic and spontaneous preterm birth

Answer 2

Spontaneous 2/3 iatrogenic 1/3

Question 3

Risk factors for spontaneous preterm birth

Answer 3

Demographic: age at extremes, elevated BMI, ethnicity
Current preg: infection, multiple preg, bleeding, polyhydramnios
Obs hx: previous T2 loss, previous preterm, previous surgical abortion
Gynae hx: cervical procedures, short cervical length
Shx: smoking, alcohol, drugs

Question 4

Preventative strategies for pre-term labour

Answer 4

1. Cervical cerclage (previous loss or known cervical problems, done at 12-14 weeks)
2. Progesterone
3. Antibiotics if symptomatic

Question 5

Who should be given steroids?

Answer 5

Women with inc. risk of delivering between 24-34+6 weeks

Two doses of betamethasone 24 hours apart.

Question 6

Hx and Ex of ?preterm labour

Answer 6

Hx:

• Labour sx: regular severe contractions, back pain, rupture of membranes, show
• Cause: bleeding, signs of infection

Exam:

• Stable or unstable
• Abdo: soft, tightenings, engagement
• Pelvic: speculum, VE, FFn

Question 7

What is fFN?

Answer 7

ECM protein that attaches decidua to foetal membranes.

Abnormal in 22-37 weeks and a/w inc. risk of preterm labour.

Falsely elevated: trauma to placenta or membranes

Question 8

Who should get MgSO4 (?preterm labour)

Answer 8

Women likely to birth <30 weeks