Preterm Labour

Question 1

Define pre-term labour

Answer 1

Onset of labour (regular, painful contractions a/w progressive cervical changes with/without ROM)

Question 2

List some complications of PTL more significant in gestations

Answer 2

HMD, ICH, infections, NEC

Question 3

Outline the management principles of PTL

Answer 3

Assess gestationEstablish the diagnosisAscertain a causeDecide on tocolysis/steroids

Question 4

Define tocolytic

Answer 4

Drug used to suppress labourIn order to administer steroids to enhance fetal lung maturity

Question 5

For how long are tocolytics continued?

Answer 5

48 hrs

Question 6

What is the dosage of nifedipine (tocolytic drug of first choice and CCB, ‘Adalat’) used in PTL?

Answer 6

Initially: 30mg orally then 20mg after 90minIf contractions persist: 20mg 6hrly

Question 7

What are two NBC/I’s to CCB (Nefidipine, ‘Adalat’)?

Answer 7

HypovolaemiaCardiac conditions

Question 8

What is the MOA of B2 adrenergic agents (e.g. salbutamol, ‘Ventolin’) as a tocolytic agent, and what are some of its S/E’s?

Answer 8

Uterine smooth muscle relaxantMaternal and fetal tachycardia, hyperglycaemia

Question 9

What are some common S/E’s of CCB (e.g. nefidipine, ‘Adalat’)tocolysis?

Answer 9

HeadacheFlushingNausea

Question 10

What is the dosage of salbutamol (Ventolin) used for tocolysis?

Answer 10

250mcg diluted in 9.5mL water as slow IV bolus

Question 11

What are 4 NB C/I to B2 adrenergic tocolysis?

Answer 11

Stenotic valvular lesionsShockDMThyrotoxicosis

Question 12

What is the MOA of prostaglandin antagonists (e.g. indomethacin) in tocolysis?

Answer 12

Blocks the conversion of AA to prostaglandin E2 and F2α

Question 13

What is the dosage of indomethacin used in tocolysis?

Answer 13

100mg rectally 12hrly for 48hrs

Question 14

What are S/E’s of prostaglandin antagonists (e.g. indomethacin) in tocolysis?

Answer 14

GIT irritationRFSupression of platelet functionPremature closure of ductus arteriosus

Question 15

What are 3 NB C/I to prostaglandin antagonist (e.g. indomethacin) tocolysis?

Answer 15

ThrobocytopaeniaPeptic ulcer diseaseFetal gestation > 32 wks

Question 16

Name the tocolytic not used in state hospitals (expensive) and outline its MOA

Answer 16

AtosibanOxytocin receptor antagonist (blocks oxytocin reeptors in the uterus)

Question 17

When may a rescue course of steroids be given?

Answer 17

If the initial dose is given at very early gestation (e.g. 27 wks)

Question 18

What did the ORACLE III trial show wrt antibiotic use in PTL?

Answer 18

No benefit except in those in whomROM had also occurred

Question 19

Define prelabour preterm ROM (PPROM)

Answer 19

Leakge of amniotic fluid through the cervixMust be differentiated from heavy vaginal dischargeor involuntary passage of urine

Question 20

List 7 causes of ROM

Answer 20

1. intra-uterine infection2. Incompetent cervix3. Iatrogenic ROM (IOL)4. Interference (a/winfection)5. Complication of amniocentesis6. Complication of ECV7. Uterine overdistension (e.g. polyhydramnios, multiple pregnancy)

Question 21

Outline the management principles of PPROM

Answer 21

> 35wks: deliver

Question 22

Outline the conservative management of PPROM

Answer 22

Bed restSterile pads changed 2hrlyAvoid PV’sAdminster steroidsAssess fetal growth, amniotic fluidMonitor for signs of maternal infection (CTG, clinical exam,twice weekly WCC + CRP)Oral antibiotics e.g. erythromycinDeliver if signs of intrauterine infection or fetal distress