Premature Labour

Question 1

Prematurity

Answer 1

Birth before 37 weeks gestation. The more premature the baby, the work the outcomes

Question 2

Non-viable

Answer 2

Below 23 weeks gestation
- Generally between 23-24 weeks = resus not considered in babies that do not show signs of life.
- From 24 weeks onwards = increased chance of survival and full resuscitation is offered

Question 3

WHO prematurity classification

Answer 3

Under 28 weeks: extreme preterm
28 – 32 weeks: very preterm
32 – 37 weeks: moderate to late preterm

Question 4

Prophylaxis of preterm labour

Answer 4

Vaginal Progesterone: Decrease activity of the myometrium and prevents the cervix remodelling in preparation for delivery. Offered to women with cervical length <25mm on USS between 16-24 weeks gestation
Cervical Cerclage: Stitch in the cervix to add support and keep it closed = Spinal or general anaesthetic. Removed when the women goes into labour or reaches term.
Cervical cerclage offered <25mm on vaginal USS between 16-24 weeks gestation, who have had a previous prem birth or cervical trauma (e.g. colposcopy and cone biopsy).
“Rescue” cervical cerclage may also be offered between 16 and 27 + 6 weeks when there is cervical dilatation without rupture of membranes, to prevent progression and premature delivery.

Question 5

Preterm labour within intact membranes definition

Answer 5

Regular painful contraction and cervical dilatation, without rupture of the amniotic sac.

Question 6

Diagnosis of preterm labour with intact membranes

Answer 6

Clinical assessment = speculum examination to assess for cervical dilatation.

< 30 weeks gestation: clinical assessment alone enough to offer Mx

> 30 weeks gestation: transvaginal USS to assess cervical length.
- USS < 15mm = Mx of preterm labour can be offered.
15mm indicates preterm labour = unlikely.

Question 7

Fetal fibronectin

Answer 7

Alternative test to TVUS = the “glue” between the chorion and the uterus and is found in the vagina during labour.
< 50ng/ml = - ve = preterm labour unlikely.

Question 8

Management

Answer 8

• Fetal monitoring (CTG)
• Tocolysis with nifedipine
• Maternal Corticosteroids
• IV Mg SO4
• Delayed cord clamping or cord milking can increase the circulating blood volumes and haemoglobin in the baby at birth

Question 8

Tocolysis

Answer 8

Using medications to stop uterine contraction
- Nifedipine = CCB
- Atosiban = oxytocin receptor antagonist = when FL CI
Used between 24 - 33 + 6 weeks gestation in preterm labour to delay delivery to help further fetal development.

Question 9

Antenatal steroids

Answer 9

Mother corticosteroids helps to develop the fetal lungs and reduce respiratory distress syndrome after delivery. They are used in women with suspected preterm labour of babies less than 36 weeks gestation.
- Two doses of intramuscular betamethasone, 24 hours apart.

Question 10

Mg SO4

Answer 10

• IV magnesium sulfate = protects fetal brain during premature delivery. reduces risk and severity of cerebral palsy.
• Given within 24 hours of delivery of preterm babies of less than 34 weeks.
• It is given as a bolus, followed by an infusion for up to 24 hours or until birth.

Question 11

How are mothers monitored for Mg SO4

Answer 11

Min 4 hourly = involves close Obvs + tendon reflexes (usually patella reflex)

Question 12

Signs of Mg SO4 toxicity

Answer 12

• Reduced respiratory rate
• Reduced blood pressure
• Absent reflexes