Enrolment difficulties.

The primary objective of this study is to assess the efficacy of a single dose of OBE001, an oral oxytocin antagonist, given for up to 7 days to delay preterm birth by 7 days compared to placebo.

The study will be a multi-centre, randomised, parallel group, double-blind, placebo-controlled study in pregnant women with threatened preterm labour between 34^0/7 and 35^6/7 weeks of gestation.

The study will be in 2 parts as follows:

• from screening until the day of delivery (including a treatment period up to seven days)
• a maternal and neonatal follow-up period from the day of delivery until 28 days post expected term date (or until 28 days post-delivery should this be later).

In addition, there will be an observational, safety follow-up of the infants for 2 years to evaluate developmental outcome.

Inclusion Criteria:

• Gestational age (GA) between 34^0/7 and 35^6/7 weeks.
• Subjects with symptoms of preterm labour.
• Subjects with a singleton pregnancy.

Exclusion Criteria:

• Foetal death in utero in current pregnancy or in previous pregnancy after gestational week 24 or expected high risk of foetal death in the current pregnancy.
• Any contraindications for the mother or the foetus to stop labour or prolong pregnancy or any maternal or foetal conditions likely to indicate iatrogenic delivery.
• Use of cervical cerclage or a pessary in situ in the current pregnancy.
• The Subject has any condition which in the opinion of the PI constitutes a risk or a contraindication for the participation of the subject in the trial.