Threatened premature labour
Table of contents
- The likelihood of premature labour becomes the greater the more of the following signs
can be identified (signs 1–3 are the easiest to identify and, when seen together,
often indicate the start of actual premature labour):
- regular, painful uterine contractions less than 10 minutes apart
- the contractions have lasted for more than an hour
- discharge of mixed blood and mucus
- bulging of foetal membranes is observed
- the cervix has disappeared
- the external os of the uterus is open to a finger.
- Cervical ripening can be assessed by using the modified Bishop score; see Antenatal clinics: care and examinations1. Cervical-length measurement using ultrasound within specialized care is more reliable than clinical examination in predicting prematurity.
- Irregular and weak uterine contractions are common during normal pregnancy.
- If labour is not in progress, the condition of the cervix is followed up at the antenatal clinic every 1–3 weeks up to pregnancy week 34.
- Inhibition of premature labour is usually not needed if the duration of pregnancy is at least 34 weeks (limit of full-term pregnancy is 37 weeks).
Linked evidence summaries
- Calcium channel blockers (nifedipine) are effective for inhibiting preterm labour compared with placebo or no treatment. They appear to be as effective as oxytocin receptor antagonist atosiban with lower costs .A
- Oxytocin receptor antagonists (atosiban) are effective for inhibiting preterm labour compared with placebo or no treatment. They appear to be as effective as calcium channel blockers (nifedipine) but with higher costs.A
- Maintenance therapy with nifedipine or atosiban appears not to be effective for preterm labour compared with placebo or no treatment.B
- Betamimetics are effective for inhibiting preterm labour compared with placebo or no treatment. Multiple adverse effects must be considered. Maintenance therapy with betamimetics after threatened preterm labour is of no benefit.A
- A course of antenatal corticosteroids to the mother accelerates fetal lung maturation in women at risk of preterm birth and reduces the risk of neonatal death, respiratory distress syndrome and several other complications.A
- Antenatal magnesium sulphate therapy for women at risk of preterm birth is effective for reducing the risk of cerebral palsy in their child.A
- Dexamethasone and betamethasone appear to be as effective for foetal lung maturation for women at risk of preterm birth, but dexamethasone may decrease intraventricular haemorrhage compared to betamethasone.B
- Antibiotic administration following preterm rupture of membranes (less than 37 weeks) is associated with a delay in delivery and a reduction in chorionamnitis.A
Betamethasone, Cervix Uteri, Fetus, Glucocorticoids, Hydroxycorticosteroids, O42*, O47.0, O60* , O80, O80-O84, Obstetrics, Parturition, Pregnancy, Premature Birth, Transportation, cervix, lung maturation, premature uterine contractions, prophylaxis, threatened premature labor, water break