Preterm Labour Flashcards
What are tocolytics?
They are medication that are used to cause uterine relaxation and stop or delay preterm labour
What is the definition of preterm labour?
It is labour that occurs before 37 weeks with regular contractions, cervical changes and rupture of membranes
What can we say is preterm labour if we do not know the gestational age of the baby?
We can classify it as preterm if the baby’s weight is <2500g
What gestational age is considered safe to deliver at as a result of the lungs being developed?
34 weeks
What are the factors that have improved the prognosis for premature babies in NICU?
- Administration of steroids
- Administering Surfactant for hyaline membrane disease
- CPAP
- Kangaroo mother care
What are the clinical signs of chorioamnionitis?
- Pyrexia
- Maternal and fetal tachycardia
- tenderness of the uterus
- Draining amniotic fluid with offensive smell
What is sub-clinical chorioamnionitis?
-it is when none of the clinical signs of chorioamnionitis are present but macroscopic or histological signs of chorioamnionitis are present
How does infection lead to preterm labour?
The bacteria ascend into the cervix and affect the membranes and placenta and enter the amniotic fluid. They release prostaglandins which then initiate contractions and lead to preterm labour
What are the maternal factors that can lead to preterm labour?
- Cervical incompetence
- Uterine factors -congenital abnormalities like septate uterus and leiomyomas
- Pyrexia from other diseases-malaria, pyelonephritis, UTI
What are the fetal factors of preterm labour?
- Multiple pregnancies and polyhydroamnios (overdistension of the uterus)
- Congenital abnormalities like neural tube defects and gastrointestinal defects causing polyhydroamnios
- Syphilis (TORCH)
What are the placental factors for causing preterm labour?
- Abruptio placentae
2. Placenta praevia
Which patients are at a higher risk of preterm labour?
- Previous preterm labour
- No antenatal care
- Smoking, alcohol
- Poor socio-economic circumstances
- Sex in the second half of pregnancy
What are Braxton hicks contractions?
These are:
- irregular
- uncomfortable but not painful
- not associated with cervical effacement and dilation
- no progressive increase in duration and frequency
How do contractions of early or preterm labour feel like?
- Regular
- Painful
- Increase in duration and frequency
- Cause cervical dilation and effacement
What is the management if the baby is being born <24 weeks?
Inevitable termination of pregnancy
What is the management if the baby is between 24-33 weeks?
Then the mom and baby has to be transferred to to a regional or tertiary hospital where there are NICU facilities
What are the tocolytics we can use to suppress labour?
- Nifedipine (adalat)
- Salbutamol
- Oxytocin receptor antagonists (atosiban)
- Indomethacin (prostaglandin inhibitor)
What is the drawback of atosiban?
It is not used in public hospitals in south Africa
What is the dose of Adalat (nifedipine) we give?
10mg three times and then increase it to 20mg 8 hourly
When do we use salbutamol the most?
When we need acute suppression of labour in the case of cord prolapse or foetal distress
What is our first choice in tocolytics?
Nifedipine-make sure you give the patient Nifedipine before we transport the patient from primary care to tertiary care
How long should we try to suppress labour by in order for steroids(betamethasone) to take full effect?
48 hours
What are the contra-indications for suppressing labour?
- Foetal distress
- Chorio-amnionitis
- Intra-uterine growth restriction
- Intra-uterine death
- Congenital abnormalities not compatible with life
- Pre-eclampsia
- Antepartum haemorrhage of unknown origin
- Pregnancy duration of >34 or <24 weeks
- Cervical dilation of >6cm
When is the use of Nifedipine (Adalat) contra-indicated in patients?
- In any hypertensive situations because it can dramatically decrease the blood pressure
- Any condition that impairs the function of the myocardium
What is the contra-indication for using salbutamol?
- Cardiac valvular lesions like mitral stenosis because the use of Nifedipine can lead to pulmonary oedema
- Diabetes mellitus because salbutamol can increase glucose
What are the side effects of using Indomethacin in the suppression of labour?
- Gastrointestinal mucosal irritation
- Renal failure
- Early closure of PDA
- Fluid retention
- Platelet dysfunction
What is the approach to suppressing labour in these patients?
- First line- Nifedipine(Adalat) 10 mg x3 tablets PO
- Second line: Salbutamol
- Third line: Indomethacin 100mg rectal suppository 12 hourly
What is the dose of Nifedipine we give?
We start by giving 10mg three times PO
- If there’s not contractions: give 20mg 8 hourly
- if there’s contractions: 20mg 3 hours after then 8 hourly
How do we mix the salbutamol?
We mix 250 mcg(0,5ml) in 10 ml syringe with 9,5 normal saline and give that over 5 minutes
-then 1000mcg in 200ml Normal saline and a 30ml/hour infusion is given and then increased to 60ml/hour if the contractions increased
What are the contra-dictions to the use salbutamol?
- Heart valve disease
- Shocked patient
- Resting tachycardia
When should we decrease the dose of salbutamol in these patients?
When the maternal HR is above 120
When is the only appropriate time to give indomethacin?
<32 weeks
This is because after 32 weeks it can lead to intra-uterine death because the closure of the PDA
What are the prophylactic antibiotics we need to give to the patient?
Ampicillin and metronidazole to treat asymptomatic chorioamniotis
What is the dose and frequency of giving steroids?
- 12mg 24hourly IV
How should we monitor the patient when administering salbutamol?
- ECG because the patient may experience tachycardia
How many doses of Indomethacin are we not supposed to exceed in a 48 hour period?
4 doses
2 dose should be adequate
Why do we not give steroids after 34 weeks?
Because the lungs have matured enough and we need to ensure that we give them between 27-34 weeks for maximum benefit
What are the dangers associated use of steroids in these patients?
- Avoid steroids if active infection is clinically evident because it causes impaired immunity
- If CD4 count is <250
- Crepitations pointing to pulmonary oedema
