What are the symptoms and treatment of preterm labour?

Symptoms and Treatment of Preterm Labor

Symptoms of Preterm Labor

Preterm labor is diagnosed by the presence of regular uterine contractions (painful or painless) accompanied by cervical change occurring before 37 weeks and 0 days' gestation. 1, 2, 3

Key Clinical Symptoms to Monitor:

• Regular uterine contractions - may be painful or painless, occurring at regular intervals 1, 2, 4
• Cervical changes - dilation and/or effacement detected on examination 2, 4, 5
• Pelvic pressure or sensation of the baby "pushing down" 1
• Low, dull backache that may be constant or intermittent 1
• Abdominal cramping with or without diarrhea 1
• Increase or change in vaginal discharge - particularly if discolored or malodorous 1
• Vaginal bleeding 1
• Rupture of membranes - leaking or gush of fluid from the vagina 1

Diagnostic Considerations:

• Clinical cervical examination remains the cornerstone of diagnosis, though it can be challenging in certain populations (e.g., women with skeletal dysplasia due to pelvic anatomy) 1
• Transvaginal ultrasound of the cervix has better accuracy and reproducibility than clinical examination alone, with cervical length between 18-30 mm being predictive of preterm delivery 4
• Less than 10% of women with a clinical diagnosis of preterm labor will actually deliver within seven days of initial presentation, highlighting the importance of accurate diagnosis 2

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Treatment of Preterm Labor

Immediate Management Algorithm:

The primary goal of treatment is to delay delivery for 48-72 hours to allow administration of antenatal corticosteroids and maternal transfer to a tertiary care facility, NOT to prevent preterm birth itself. 6, 7

1. Corticosteroids (Priority Intervention)

• Administer antenatal corticosteroids to all women at risk of preterm delivery between 24-34 weeks' gestation 1, 6
• This is the only intervention proven to improve neonatal outcomes, including reduction in neonatal mortality, intracranial hemorrhage, necrotizing enterocolitis, and neonatal infection 2
• Consider corticosteroids for women at ≤34 weeks remaining at high risk of preterm delivery 14 days or more after initial course (rescue dose) 1

2. Tocolytic Therapy (24-34 Weeks)

Tocolytics should be used between 24-34 weeks' gestation to delay delivery 48-72 hours for corticosteroid administration and maternal transfer. 6, 7

First-Line Tocolytic Agents:

• Nifedipine (calcium channel blocker) - may delay delivery 48-72 hours in women with intact membranes after 26 weeks 7
• Indomethacin (NSAID) - may delay delivery 48-72 hours in women with intact membranes after 26 weeks 7
• Magnesium sulfate - used as tocolytic, but primary benefit is for fetal neuroprotection rather than labor inhibition 7, 8

Critical Caveat:

No tocolytic has been consistently shown to improve perinatal mortality or long-term neonatal outcomes - their sole purpose is buying time for corticosteroids and transfer 6, 7, 2

3. Magnesium Sulfate for Neuroprotection

• Administer magnesium sulfate for fetal neuroprotection if less than 32 weeks' gestation 6, 7
• Reduces incidence of cerebral palsy when given before anticipated early preterm birth 7, 2
• WARNING: Continuous administration beyond 5-7 days can cause fetal hypocalcemia, skeletal demineralization, osteopenia, and bone abnormalities 8
• Monitor serum magnesium levels (therapeutic range: 3-6 mg/100 mL or 2.5-5 mEq/L), patellar reflexes, and respiratory rate 8

4. Hydration

• Standard management includes intravenous hydration in an attempt to stop contractions 1
• In women with skeletal dysplasia or small stature, adjust fluid volumes proportionately to avoid fluid overload - do not use standard 1L preloading protocols 1

5. Group B Streptococcus (GBS) Prophylaxis

• Obtain vaginal-rectal swab for GBS culture at hospital admission for women presenting with preterm labor before 37 weeks, unless GBS screen performed within preceding 5 weeks 1
• Start GBS prophylaxis immediately if GBS status unknown or positive within preceding 5 weeks 1
• Discontinue GBS prophylaxis if patient not in true labor 1

6. Maternal Transfer

• Arrange immediate transfer to tertiary care facility with appropriate NICU capabilities if not already at such a facility 6, 7

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Special Circumstances

Advanced Cervical Dilation (≥7 cm):

At 7 cm cervical dilation, prepare for imminent delivery rather than attempting futile tocolysis. 6

• Ensure corticosteroids administered if between 24-34 weeks 6
• Give magnesium sulfate for neuroprotection if <32 weeks 6
• Prepare neonatal resuscitation team 6

Preterm Premature Rupture of Membranes (PPROM):

• Monitor for signs of infection: fever, contractions, vaginal bleeding, discolored/malodorous discharge, abdominal pain 1
• Daily temperature monitoring essential 1
• Obtain GBS culture and start antibiotics for latency or GBS prophylaxis 1
• Hospital readmission indicated for hemorrhage, infection, or fetal demise 1

Contraindications to Tocolysis:

• Tocolytic therapy generally not recommended when delivery would be beneficial for maternal or fetal indications 7
• Avoid in presence of intraamniotic infection, significant vaginal bleeding, or fetal compromise 7

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Common Pitfalls to Avoid

• Do not rely on tocometry alone - it identifies more contractions but does not improve diagnosis or prognosis 4
• Do not continue magnesium sulfate beyond 5-7 days due to risk of fetal bone abnormalities 8
• Do not use standard fluid volumes in women with small stature - adjust proportionately to avoid fluid overload 1
• Do not assume all women with contractions are in true preterm labor - remember that <10% will deliver within 7 days 2
• Do not forget GBS prophylaxis in the acute management of preterm labor 1