Regular uterine contractions and cervical changes before 37 weeks LMP.
4.10.1 Risk factors
– Preterm rupture of membranes before 37 weeks LMP
– Maternal infection
– Pregnancy-related disorder (e.g. pre-eclampsia, polyhydramnios, placenta praevia)
– Multiple pregnancy
– Cervical insufficiency
– Age < 18 years
– Look for and treat any maternal infection; always perform urinalysis (dipstick test); perform rapid malaria test in endemic areas.
– Let the woman deliver:
• If > 34 weeks LMP and membranes have ruptured.
• If labour is too advanced to be stopped (cervix effaced, 5 cm dilation), no matter what gestational age.
• If the mother’s life is threatened (poor general condition, pre-eclampsia, eclampsia, abruptio placentae, severe haemorrhage, etc.), no matter what gestational age.
• If foetal death is confirmed (no foetal movements and no foetal heart tones 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 may be enough for mild forms (contractions but no cervical changes).
• Tocolytic therapy:
The main objective is to postpone delivery in order to administer corticosteroids for accelerating foetal lung maturation.
nifedipine PO (immediate release tablet): 10 mg to be repeated every 15 minutes if uterine contractions persist (max. 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. Duration of the treatment is 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 antibiotherapy 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: consider episiotomy, even if the foetus is small; before 34 weeks LMP vacuum extraction is contra-indicated, use forceps if instrumental extraction is required.
– Prepare for neonatal resuscitation (Chapter 10, Section 10.2). Closely monitor neonate's temperature (risk of hypothermia) and blood glucose (risk of hypoglycaemia).
4.10.4 Preventing preterm delivery
– Treatment of infections and other disorders during pregnancy.
– Rest for women with predisposing factors: multiple pregnancy, polyhydramnios, previous preterm delivery.