4.10 Threatened preterm delivery

Regular uterine contractions and cervical changes before 37 weeks LMP.

4.10.1 Causative factors

– Premature rupture of membranes
– Infection, fever
– Pregnancy-related disorder: pre-eclampsia, polyhydramnios, placenta praevia
– Malnutrition
– Multiple pregnancy
– Cervical incompetence, immature uterus in the young primipara

4.10.2 Management

– Always look for malaria (rapid test) and urinary tract infection (dipstick test); treat the apparent causes.

– Let the woman deliver:
• If she is > 34 weeks LMP and her waters have broken.
• If labour is too advanced to be stopped (cervix effaced, 4 cm dilation), no matter what gestational age.
• If the mother’s life is threatened (very poor general condition, pre-eclampsia, eclampsia, abruptio placentae, etc.), no matter what gestational age.
• If foetal death is confirmed (no foetal movements and no foetal heart tone at several checks or ultrasound confirmation of foetal death).

– Otherwise, try to stop the contractions:
• Strict bed rest in a medical setting. Bed rest alone is enough in mild forms (contractions without cervical changes).
• Tocolytic therapy:
The main objective is to postpone delivery in order to administer corticosteroids for accelerating foetal lung maturation:

nifedipine PO
capsule 10 mg)

10 mg to be repeated every 15 minutes if uterine contractions persist (maximum 4 doses or 40 mg), then 20 mg every 6 hours

Never administer sublingually (risk of placental hypoperfusion and foetal death); always use the oral route.

or, if not available

IV infusion
(0.5 mg ampoule)

Salbutamol has numerous contra-indications (see the MSF handbook Essential Drugs).

Dilute 5 mg (ten 0.5 mg ampoules) in 500 ml of 5% glucose or 0.9% sodium chloride, to obtain a 10 micrograms/ml solution.
Start at a rate of 15 to 20 micrograms/minute (30 to 40 drops /minute).
If contractions persist, increase the rate by  10  to  20  drops/minute every  30 minutes until contractions stop. Do not  exceed  45  micrograms/minute (90 drops/minute).
Maintain the effective rate for one hour after contractions stop then, reduce the rate by half every 6 hours.
Monitor the mother’s heart rate regularly, and reduce the rate in the event of maternal tachycardia (> 120 beats/minute).

Duration of the treatment is 48 hours, regardless of which drug is used.

Do not combine nifedipine and salbutamol.

Salbutamol IV administration requires the constant presence of qualified personnel capable of appropriate medical supervision. If the infusion cannot be properly monitored, administer the salbutamol by IM route: 0.5 mg every 6 hours for 48 hours.

– Prepare the foetus for preterm birth:
After 26 weeks LMP and before 34 weeks LMP, help lung maturation with dexamethasone IM: 6 mg every 12 hours for 48 hours. In case of severe maternal infection, start antibiotic therapy prior to dexamethasone.

4.10.3 Preterm delivery

– Delivery is usually rapid and often breech.

– Avoid aggressive treatment (drugs or procedures), but above all, avoid a long labour. Expulsion should be rapid: possible episiotomy, even if the foetus is small; vacuum extraction is contra-indicated before 34 weeks LMP—if possible, use forceps if instrumental extraction is required.

– Provide for a good warming control (kangourou mother care, cap) and newborn resuscitation. Monitor temperature (risk of hypothermia) and blood glucose (risk of hypoglycaemia).

4.10.4 Preventing preterm delivery

– Treatment of infections and other disorders during pregnancy.

– Bed rest for women with predisposing factors: multiple pregnancy, polyhydramnios, previous preterm delivery, tired grand multipara.