Dose Reduction of Antenatal Betamethasone Given to Prevent the Neonatal Complications Associated With Very Preterm Birth

The BETADOSE project consist in a randomized, multicenter, double blind placebo-controlled non inferiority trial comparing a standard dose regimen (24 mg) to a reduced dose regimen (12 mg) of betamethasone given to prevent the neonatal complications associated with very preterm birth.A betamethasone course consists in 2 injections of 12 mg betamethasone 24 hours apart for a total dose of 24 mg.

The first injection will be unmasked in both group. In both group, women will receive a first 12 mg injection of betamethasone according to local protocols.

Randomization will be performed after the first injection. Women will then receive either a placebo injection (reduced dose regimen, 12 mg only from the first injection) or a second 12 mg betamethasone injection (standard dose regimen, 12 mg from the first injection and 12 mg from the second injection=24 mg). This protocol allows women sent from level 1 and 2 to level 3 perinatal centers after having already received their first injection to participate.

In case of multiple antenatal betamethasone courses, women will receive their second course according to the same design as in their first course.

Inclusion criteria

• Singleton pregnancy
• Patient Having receipt the first injection of betamethasone and pregnancy term < 32 weeks of gestation
• Age > 18 years
• Patient affiliated to a social security regime

Exclusion criteria

• Chromosomal aberrations and major fetal malformations
• Cervical dilatation ≥ 4 cm and of cervical length ≥20mm.
• Patient who have already received a first course of betamethasone
• first intravenous injection of betamethasone