Preterm Labour

Question 1

Define PROM

Answer 1

Chorio-amniotic membrane rupture before onset of labour

Premature rupture

Question 2

Diagnosis PROM? (5)

Answer 2

• Maternal history + sterile speculum: pool of fluid in vagina - amiorrhexis
• microscopic examination of vaginal fluid: characteristic ferning pattern
• nitrazine test: ph of vaginal fluid (Amniotic range 7 - 7,3)
• amniosure / aminiosense ( panty liner that changes colour at ph > 5); dipstix; litmus paper
• ultrasound: oligohydramnios to help confirm diagnosis

Question 3

Management PROM? (10)

Answer 3

• Admit
• maternal surveillance for signs chorio amnionitis
• foetal surveillance with daily ctg
• antibiotics
  → erythromycin 500 mg 6 hourly po for 10 days or
  → ampicillin 2g qid for 48 hours + then amoxicillin 500 mg po TDS 5 days + azithromycin 500mg daily po 3 days.
  → add metronidazole 400 mg TDS po for 5 days if going for c/s
  → treatment cervical chorio amnionitis : deliver + ampicillin 2 g bid iv + gentamycin 240 mg daily iv
• inhibit uterine contractions (tocolysis)
• glucoconticosteroids: only use for 24 hours with concurrent administration antibiotics and corticosteroids and absence of chorio amnionitis
• mgso4 24 - 32 weeks + imminent delivery
• amnionfusion for prolonging Latency: 250 ml isotonic normal saline associated with increase in latency from 9-21 days
• timing of delivery: consider from 34 weeks

Question 4

Define preterm labour

Answer 4

Uterine contractions > 4/20 mins and cervical changes with intact membranes
< 37 weeks

Question 5

Define term pregnancy

Answer 5

37.0 weeks - 41.6 weeks

Question 6

Define early term pregnancy

Answer 6

37.0 weeks- 38.6 weeks (higher neonatal MM. )

Question 7

Name 4 risk factors preterm labour

Answer 7

• Prior preterm birth
• cervical length < 25 mm before 24 weeks gestation
• history cervical surgery: conisation, lletz
• behavioural: low maternal pre-pregnancy weight, smoking

Question 8

Primary Prevention preterm labour? (6)

Answer 8

Primary: all women - screening

• single cervical length assessment between 18 - 22 weeks
• screen and treat asymptomatic bacteruria if urine colony count > 10^5
• decrease rate multiple gestation from assisted reproduction
• smoking cessation
• reduce Occupational fatigue: avoid work > 42 hours week or stand > 6 hours/ day
• avoid short inter-pregnancy interval: < 6 months high risk
• screen for HIV, ANC, educate, avoid extremes of age

Question 9

Secondary prevention preterm labour? (5)

Answer 9

Secondary: women with risk factors

• if previous preterm: regular cervical length screening after 16 weeks
• progesterone: cervical length <25 mm
• cervical circlage: history preterm and short cervix, or elective if 3 or more second trimester miscarriage
• trans abdominal circlage: previous failed cervical circlage, inability to perform cervical circlage
• twin gestation: vaginal progesterone. No benefit cerclage or pessary

Question 10

Tertiary prevention preterm labour?

Answer 10

Initiated after parturition (giving birth) with goal of improving outcomes for infants

Question 11

Approach to preterm labour? (5)

Answer 11

• Sterile speculum to rule out ROM
• consider uterine culture
• continuous ctg

Determine If 3cm dilated or cervical change
< 3cm dilated or no cervical change

Question 12

Which gestational age and foetal weight is considered to have lower risk perinatal mortality, and can be delivered if necessary?

Answer 12

> 34 weeks
2 kg

Question 13

Management preterm labour with 3cm dilated or cervical change? (7)

Answer 13

• Corticosteroids
• Consult NICU
• establish foetal presentation, EFW, AFI ( amniotic fluid index), placental location
• consider amniocentesis to rule out infection; consider antibiotics (GBS)
  /
  Tocolyse
• 26 weeks - 31.6 weeks
  → indomethacin 50 - 100 mg load , then 25 -50 mg 6 hourly x 24 h
  → consider mgso4 if delivery imminent in 24 hours
• 32 - 33.6 weeks
  → nifedipine 10 mg po every 15 min X4. Continue 10-20 mg 6 hourly x 24 h. Bp > 90/50

Question 14

Management preterm labour with < 3cm dilated or no cervical change? (4)

Answer 14

Perform TVS CL (cervical length )

• <20 mm → suggest admission, steroids, tocolyse. Consider amniocentesis to rule out infection
• 20 - 29 mm
  → if contractions persist, observe and consider repeat TVS CL
  > persistent contractions with cervical change → follow protocol + tocolyse
  > stable: discharge home
• > 30 mm → discharge

Question 15

Dose indomethacin for tocolysis?

Answer 15

Load 50 - 100 mg
Then
25 - 50 mg 6 hourly
X 24 hours

Question 16

Dose nifedipine for tocolysis?

Answer 16

10 mg po every 15 minutes x 4
Cont: 10 - 20 mg po 6 hourly
X 24 hours

Question 17

Dose mgs04 for foetal neuroprotection?

Answer 17

Viability - 32 weeks if imminent delivery next 24 hours

Loading: 4g in 200 ml ns given slowly over 20-30 min
Maintenance: 1 G iv per hour for 12 hours

It delivery occurs before completion, discontinue. Don’t repeat course

Question 18

Define PPROM

Answer 18

Chorio-amniotic membrane rupture before onset of labour before 37 weeks gestation

Preterm premature rupture of membranes