Preterm labour

Question 1

What is pre term labour?

Answer 1

Labour between 24-37 weeks

7-8% babies born in UK

50% perinatal deaths

Question 2

Categories of PTB

Answer 2

Moderate-late PTB: 32-37 weeks

Very PTB: 28-32 weeks

Extreme PTB: <28 weeks

Question 3

At what stage is a foetus viable?

Answer 3

24 weeks or >500g

Question 4

Risk factors for PTB

Answer 4

• Previous PTB or late miscarriage
• Multiple pregnancy
• Cervical surgery
• Uterine anomalies
• Pre-eclampsia

Question 5

Investgations in preterm labour

Answer 5

FBC: anaemia, raised WCC

Swabs: MSU, infection

USS for foetal presentation and weight

Foetal fibronectin/ transvaginal USS

Cervix dilate >3cm = PT labour

Question 6

How can preterm labour be predicted?

Answer 6

Transvaginal USS of cervix

The shorter the cervix the higher the risk of delivery - if cervix is 5mm long @ 23 weeks 78% of delivery <32 weeks

• If cervix is >15mm 1% risk of delivery within 7 days
• If cervix is <15mm 49% risk within 7 days

Question 7

Preventing PTB

Answer 7

Women with RFs: refer to specialist clinics early in pregnancy

Clindamycin for BV

Progesterone for high risk women: little benefit in multiple pregnancies

Cervical suture (cerclage): no benefit in multiple pregnancy

Question 8

How is preterm labour managed?

Answer 8

Establish whether real or threatened based on cervical length and foetal fibronectin

Admit if risk is high

Check foetal presentation

Steroids IM betamethasone 2 doses

Consider tocolytics to inhibit contractions and delay delivery

Give antibiotics if labour confirmed

15% chance survival @ 23 weeks

80% survival @ 25 weeks

<26 weeks only 20% are disability free

Question 9

What is PROM?

Answer 9

ROM <37 weeks

Major cause of preterm labour

Risk of sepsis

2% pregnancies

Question 10

Risk factors for PROM

Answer 10

Smoking

Antepartum haemorrhage

Previous PTB

Infection

Question 11

What is chorioamnionitis

Answer 11

Infection of amniotic fluid

Increases baby morbidity and mortality

Suggestive features: fever, malaise, abdo pain, offensive discharge, pyrexia, tachycardia, uterine tenderness, foetal tachycardia

Question 12

Investogations for PROM

Answer 12

FBC, WCC, CRP

Swabs

MSU

USS, EFW

Avoid V/E as increased risk of infection

Question 13

Management of PROM

Answer 13

a) Evidence of chorioamnionitis

• Betamethasone, deliver irrespective of gestation, broad spec antibiotics

b) No evidence of chorioamnionitis

Admit

Inform SCBU

Betamethasone

Erythromycin

Question 14

Which antibiotic is associated with increased risk of NEC?

Answer 14

Co-amoxiclav

Question 15

What is prolonged pregnancy?

Answer 15

Pregnancy that exceeds 42 weeks/ 294 days from LMP in women with regular 28 day cycles

3-10% pregnancies

30% chance if previous prolonged pregnancy

Question 16

Maternal risks in orolonged pregnancy

Answer 16

Anxiety

Risk of induction/ operative delivery

Question 17

Foetal risks of prolonged pregnancy

Answer 17

Intrapartum death 4x higher

Early neonatal death 3x higher

Meconium aspiration

Macrosomia + shoulder dystocia

Foetal distress

Growth restriction

Question 18

What is foetal post-maturity syndrome?

Answer 18

Post-term infants who show signs of malnutrition

Scaphoid abdomen

Little subcut fat

Peeling skin on hands and feet

Overgrown nails

Anxious look

Question 19

Management of prolonged pregnancy

Answer 19

EDD: be as accurate as possible

Stretch and sweep @ 41 weeks

Induction @ 41-42 weeks

Foetal monitoring daily after 42 weeks and counsel those who don’t want intervention