What is the management of preterm labour?

Management of Preterm Labour

The management of preterm labour requires individualized counseling about maternal and fetal risks and benefits of both abortion care and expectant management, with all patients with previable and periviable preterm prelabor rupture of membranes (PPROM) being offered abortion care, while expectant management can also be offered in the absence of contraindications. 1

Diagnosis and Initial Assessment

• Initial assessment should include evaluation for signs of infection, placental abruption, and fetal well-being 2
• Fetal biometry, amniotic fluid volume assessment, and fetal Doppler waveform analysis should be performed at first diagnosis 2
• Intraamniotic infection is diagnosed clinically based on maternal temperature ≥38°C and other signs (maternal tachycardia, purulent cervical discharge, fetal tachycardia, uterine tenderness) 1
• Some cases of intraamniotic infection may not initially present with maternal fever, so diagnosis and intervention should not be delayed due to absence of fever 1

Management Based on Gestational Age

Previable PPROM (<20 weeks)

• All patients should be offered abortion care due to high maternal risks and poor fetal outcomes 1, 2
• Expectant management can be offered in absence of contraindications 1
• Shared decision-making is recommended regarding antibiotic use 3
• Contraindications to expectant management include intraamniotic infection, hemorrhage, and fetal demise 1

Periviable PPROM (20-23 6/7 weeks)

• Both abortion care and expectant management options should be discussed 1, 2
• Antibiotics can be considered to prolong latency (GRADE 2C) 1, 3, 2
• Maternal risks are significantly higher with expectant management compared to abortion care 1
• Neonatal survival rates vary from 17% to 80%, with approximately 20% surviving after PPROM at 16-19 weeks, 30% after PPROM at 20-21 weeks, and 41% after PPROM at 22-23 weeks 1

PPROM at ≥24 weeks

• Antibiotics are strongly recommended (GRADE 1B) 1, 3, 2
• Antenatal corticosteroids should be administered between 24+0 and 34+0 weeks gestation 3, 2
• Magnesium sulfate is recommended for fetal neuroprotection when delivery is anticipated before 32 weeks 3, 2

Pharmacological Management

Antibiotics

• A 7-day course of antibiotic therapy with IV ampicillin and erythromycin for 48 hours followed by oral amoxicillin and erythromycin for 5 days is recommended 2
• Azithromycin can replace erythromycin if unavailable 3, 2
• Avoid amoxicillin-clavulanic acid due to increased risk of necrotizing enterocolitis 3, 2

Antenatal Corticosteroids

• Recommended between 24+0 and 34+0 weeks gestation to accelerate fetal lung maturity 3, 2
• Not recommended until the time when neonatal resuscitation and intensive care would be considered appropriate 1, 3

Magnesium Sulfate

• Recommended for fetal neuroprotection when delivery is anticipated before 32 weeks 3, 2
• Should be used with caution in patients with renal impairment 4
• Monitor for signs of magnesium toxicity including diminished deep tendon reflexes and respiratory depression 4
• Continuous administration beyond 5-7 days can lead to fetal hypocalcemia and bone abnormalities 4

Monitoring and Follow-up

Inpatient Management

• Initial observation in hospital is reasonable to ensure stability 2
• Monitor for signs of maternal complications such as hemorrhage or infection 2
• Urine output should be maintained at ≥100 mL during four hours preceding each magnesium sulfate dose 4

Outpatient Management

• Can be considered after stability is confirmed 2
• Should include daily temperature monitoring to screen for maternal fever 1
• Weekly outpatient visits for assessment of maternal vital signs, fetal heart rate, physical examination, and possible laboratory evaluation 2
• Hospital readmission is indicated for hemorrhage, infection, fetal demise, or when reaching viability for administration of antenatal corticosteroids and magnesium sulfate 2

Special Considerations

Cerclage Management

• Similar to cerclage management after PPROM at later gestational ages 1, 2
• Reasonable to either remove cerclage or leave it in situ after discussing risks and benefits (GRADE 2C) 1, 2

Interventional Procedures

• Serial amnioinfusions and amniopatch are considered investigational and should only be used in clinical trial settings (GRADE 1B) 1, 2

Maternal Risks and Outcomes

• Expectant management increases risk of maternal complications including infection, hemorrhage, and death compared to abortion care 1
• Composite maternal morbidity is higher with expectant management compared to abortion care (60.2% vs 33.0%) 1
• Intraamniotic infection occurs in 38.0% of those choosing expectant management vs 13.0% choosing abortion care 1
• Maternal sepsis has been reported in up to 6.8% of cases of previable and periviable PPROM 1
• Maternal mortality rate associated with expectant management of PPROM at 14-24 weeks is approximately 45 per 100,000 patients 1
• Once infection is identified, median time to death can be as short as 18 hours, illustrating how rapidly clinical condition can deteriorate 1

Common Pitfalls to Avoid

• Delaying diagnosis and treatment of intraamniotic infection due to absence of maternal fever 1
• Using amoxicillin-clavulanic acid, which increases risk of necrotizing enterocolitis 3, 2
• Prolonged or repeated antibiotic courses beyond what would be used for PPROM at later gestational ages 3
• Administering antenatal corticosteroids and magnesium sulfate before the time when neonatal resuscitation would be appropriate 1, 3