Preterm birth (PTB) is a major cause of perinatal morbidity and mortality [1]. Despite advances in obstetric care, the rate of PTB is increasing, as the ability to accurately predict preterm labour remains elusive [2, 3]. This is, in part, because the aetiology of preterm labour is multifactorial [4]. Early prediction and identification of those at risk of preterm birth would provide the opportunity to target interventions to prevent preterm labour, such as progesterone and cerclage. Moreover, it would facilitate the provision of optimised care to infants born preterm, such as the timely administration of antenatal corticosteroids.