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Information ⬇

Editors

AnitaVirtanen
KatiTihtonen

Threatened Premature Labour

Essentials

  • Signs of beginning labour
    • Regular, painful uterine contractions 10 minutes or less apart for > 1 h
    • Recurrent or significant bloody discharge or discharge containing blood and mucus
    • Suspected preterm premature rupture of membranes (PPROM)
    • Cervical ripening
  • Drug therapy
    • Tocolysis with nifedipine will delay delivery slightly to gain time for
      • glucocorticoids to mature the foetal lungs
      • magnesium sulphate to reduce the risk of cerebral palsy.
  • Glucocorticoids should be given until week 34+6 of pregnancy; subsequently, delivery should no longer be prevented.
  • A gynaecologist should be consulted.
  • If the membranes have ruptured, the mother should be transported to hospital in a supine position to avoid umbilical cord prolapse.

Definition and epidemiology

  • Birth is defined as a delivery taking place after week 22+0 of pregnancy or after reaching a birth weight of 500 g.
  • Labour is premature if occurring before week 37+0 of pregnancy.
    • The most common underlying factor is an infection.
  • Threatened premature labour is preterm premature rupture of membranes or regular contractions ripening the cervix before week 37+0 of pregnancy.
    • About 2 out of 3 cases of spontaneous premature labour start with contractions and the rest with rupture of the membranes.
  • The rate of premature labour varies across countries between 4% and 16% http://www.who.int/news-room/fact-sheets/detail/preterm-birth.
    • In Finland, an average of 5% of babies are born before week 37+0 of pregnancy and less than 1% before week 32+0.
      • Half of twins, and all triplets, are born prematurely.
  • Classification of premature labour
    • Spontaneous, due to contractions and preterm ripening of the cervix
    • Due to preterm premature rupture of membranes
    • Iatrogenic, associated with pregnancy complications

Risk factors

  • The primary risk factors
    • History of premature labour or second trimester miscarriage
    • Multiple pregnancy
    • Uterine malformations or previous cervical surgery
    • Recurrent bleeding during pregnancy
    • Assisted pregnancy
    • Poorly controlled chronic maternal diseases
    • Smoking or use of illegal drugs
  • In about one case in three, there is no known risk factor.
  • Risk factors do not include sauna bathing, physical exercise, intercourse or drinking coffee.

Preterm premature rupture of membranes Antibiotics for Preterm Rupture of Membranes, Planned Early Birth Versus Expectant Management for Women with Preterm Prelabour Rupture of Membranes for Improving Pregnancy Outcome, Early Versus Delayed Umbilical Cord Clamping in Preterm Infants, Antenatal Corticosteroids for Fetal Lung Maturation for Women at Risk of Preterm Birth

  • In about 30-40% of cases, premature labour begins after preterm premature rupture of membranes.
  • After rupture of membranes, the mother should be monitored at a hospital, and broad-spectrum antimicrobials should be given for at least 3 days Antibiotics for Preterm Rupture of Membranes.
    • Further treatment depends on the clinical status.
  • After preterm premature rupture of membranes, pregnancy may continue for several days/weeks if no signs of infection or other abnormality develop.
  • Problems associated with preterm premature rupture of membranes include chorioamnionitis, placental dysfunction and placental abruption.

Symptoms and signs

  • Painless, irregular contractions belong to normal pregnancy.
    • They are often felt as tightness and hardening of the uterus.
  • Signs of beginning labour
    • Regular, painful contractions
    • Discharge of mixed blood and mucus
    • Lower abdominal/back pain
  • On bimanual pelvic examination, softening, shortening and opening of the cervix suggest cervical ripening.
  • In addition, the presenting part may be palpable low in the pelvis.

Indications for emergency referral

  • Regular, painful uterine contractions 10 minutes or less apart for > 1 h
  • Recurrent or significant bloody discharge or discharge containing blood and mucus
  • Suspected preterm premature rupture of membranes
  • Foetal membranes visible on speculum examination and duration of pregnancy < 35 weeks
  • Irregular contractions or a feeling of pelvic pressure and ripening of the cervix before week 35 of pregnancy

Treatment of threatened premature labour Foetal Fibronectin Testing for Reducing the Risk of Preterm Birth, Treatment of Premature Rupture of Membranes, Magnesium Sulphate for Preterm Labour, Home Uterine Activity Monitoring for Detection of Preterm Labour, Bed Rest for Preventing Preterm Birth, Cervical Stitch (Cerclage) for Preventing Preterm Birth in Singleton Pregnancy, Maintenance Therapy with Calcium Channel Blockers or Oxytocin Antagonists for Preventing Preterm Birth, Oxytocin Receptor Antagonists for Inhibiting Preterm Labour, Magnesium Sulphate for Women at Risk of Preterm Birth for Neuroprotection of the Foetus, Prenatal Administration of Progesterone for Preventing Preterm Birth, Calcium Channel Blockers for Inhibiting Preterm Labour, Betamimetics for Preterm Labour, Dexamethasone Vs Betamethasone for Fetal Lung Maturation for Women at Risk of Preterm Birth, Antenatal Corticosteroids for Fetal Lung Maturation for Women at Risk of Preterm Birth, Nitric Oxide Donors for Delaying Preterm Birth, Repeated Exposure to Antenatal Corticosteroids

Evidence Summaries ⬆