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.
- 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
- The aim of tocolytic therapy is to prolong pregnancy so as to gain time to
- hospitalize the mother (tertiary care hospital if at < 32 weeks of pregnancy)
- give glucocorticoid therapy to mature the foetal lungs, and, as necessary, magnesium sulphate.
- Tocolysis (consult a gynaecologist on starting the treatment)
- Magnesium sulphateMagnesium Sulphate for Women at Risk of Preterm Birth for Neuroprotection of the Foetus can be used for neuroprotection before week 32 of pregnancy to reduce the risk of cerebral palsy. It should be given as close to birth as possible.
- Antenatal glucocorticoid therapy Antenatal Corticosteroids for Fetal Lung Maturation for Women at Risk of Preterm Birth is given to accelerate foetal lung maturation in threatening premature delivery in weeks 22+5 - 34+6 of pregnancy.
- Deliveries < 32 weeks of pregnancy should take place at a centre with special expertise (tertiary care hospital).
- The delivery method should be chosen individually.
- The choice depends on the cause of prematurity, duration of pregnancy and presentation.
Evidence Summaries ⬆