Onset of labour before 37 weeks

Question 1

Definition of preterm labour

Answer 1

Onset of labour from >20 weeks until 36 + 6 days

Question 2

Common associations (8)

Answer 2

Lower SES
Previous preterm
Multiple pregnancy
Uterine structural, cervical incompetence
Infection and PPROM
APH
Polyhydramnios
\+Fetal fibronectin and short cervical length
Poor dental hygeine
Low maternal weight

Question 3

Causes of mortality and morbidity in preterm (7)

Answer 3

Respiratory distress
Hypothermia
Hypoglycemia
Necrotising enterocolitis
Jaundice
Infection
Retinopathy of prematurity

Question 4

Assessment: mother and fetus

Answer 4

Mother:
History->
Bleeding, fluid, discharge
Dysuria, frequency, flank pain, fever
Polyhydramnios->++girth, ?diabetes
Multiples
Previous preterm, uterine structural
Previous investigations and procedures->CIN, ablation, sutures
Family and social history->poor nutrition, smoking, single, coffee, recreational drugs, alcohol, poor dental hygeine.
Medical, surgical, obstetric

Fetal;
Movement, lie and presentation

Assess for signs and symptoms:
Pelvic pressure, lower abdominal cramping, lower black pain. Vaginal loss. Regular uterine activity

Question 5

How is diagnosis made

Answer 5

Presence of regular painful contractions with dilitation and effacement of cervix on sterile speculum/vaginal examination (to avoid in PPROM b/c risk infection)

Question 6

How id diagnosis of chorioamnionitis made

Answer 6

>37.5
Abdominal pain
Uterine tenderness
Fetal tachycardia/maternal tachycardia
Offensive vaginal discharge

Question 7

Risk of preterm with previous preterm

Answer 7

4X risk

Question 8

Key diagnostic features

Answer 8

Risk factors
Uterine contraction
PPROM
\+Cervical dilitation
Cervical length

Question 9

What is threatened preterm labour

Answer 9

Preterm uterine contractions without cervical effacement or dilation

Question 10

What is involved in diagnosis

Answer 10

Establishing likelihood of delivery
Determining fetal well being
Looking for underlying cause

Question 11

What gives the best prediction of preterm birth

Answer 11

Fetal fibronectin + cervical ulrasound

Question 12

When are contractions less likely to be physiological

Answer 12

When >1 in 10 minutes

Question 13

Physical examination

Answer 13

Vital signs
Abdominal palpation
Fetal surveillance->CTG and tocograph
Sterile speculum:
->identify if ROM
->assess cervix
->high vaginal swab
->test for fetal fibronectin
Low vaginal/anorectal GBS swab
Cervical dilitation->sterile digital vaginal examination unless ROM, PP
USS if available->assess fetal growth and well being

Question 14

Investigations to confirm premature labour

Answer 14

Fetal firbonectin
High vaginal/cervical swabs for bacterial infection/Chlamydia/->MCS
Low vaginal for GBS
MSU for MCS

Question 15

What is fetal fibronectin, how performed and when

Answer 15

All women presenting with preterm contractions between 24 and 35 weeks’ gestation, who are not in advanced labour (cervical dilation

Question 16

When to consider admission (7)

Answer 16

fFN >50ng/ml or
Cervical dilation ot
Cervical change over 2-4 hours or
ROM or
Contractions regular and painful or
Further Ix/management required or
Maternal/fetal concerns

Question 17

Management on admission

Answer 17

Analgesia
Clinical surveillance
CTG/fetal monitoring
Transvaginal cervical length if available
Consult
Plan care, prepare for birth

Consider:
In utero transfer
Antenatal steroids
Tocolysis
Antibiotics
Magnesium sulphate

Question 18

Management if admission not required

Answer 18

Provide information re: signs and symptoms and returning for care
Arrange follow up as indicated

Question 19

Antenatal corticosteroid regime

Answer 19

o Betamethasone: 11.4 mg IM then 2nd dose in 24 hours
o Consider 2nd dose at 12 hours if PTB likely within
24 hours
• If risk of PTB remains ongoing in 7 days, repeat dose

Question 20

Tocolysis regime

Answer 20

• Nifedipine 20 mg oral
• If contractions persist after 30 minutes repeat
Nifedipine 20 mg oral
• If contractions persist after further 30 minutes repeat
Nifedipine 20 mg oral
• Maintenance therapy 20 mg every 6 hours for 48
hours
Discuss with Obstetrician/Paediatrician
• If contraindications exist
• If other options required (Indomethacin, Salbutamol)

Question 21

Administer antibiotics if

Answer 21

Established labour w/ imminent risk of preterm birth
Evidence of chorioamnionitis
o Ampicillin (or Amoxycillin) 2 g IV initial dose, then
1 g IV every 4 hours
o Gentamicin 5 mg/kg IV daily
o Metronidazole 500 mg IV every 12 hours

If X labour and:
Membranes intact->cease
PPROM->convert to Erythromycin 250mg oral 6qh for 10 days

If hypersensitivity->lincomycin or clindamycin

Question 22

Vaginal or cesarean birth

Answer 22

Recommend vaginal unless specific CI/maternal condition necessitates C section

Question 23

Management after threatened preterm labour

Answer 23

Care according to clinical needs
Maternal and fetal assessments
T/F back to referring hospital if feasible
D/C when criteria met
Inform woman, GP, care provider about further recommendations of care

Question 24

Magneium sulphate regime

Answer 24

• Gestational age 24–30 weeks
• Labour established or birth imminent
o Loading dose: 4 g IV bolus over 20 minutes
o Maintenance dose: 1 g/hour for 24 hours or until
birth – whichever occurs first