Maud D van Zijl,1 Bouchra Koullali,1 Ben WJ Mol,2 Eva Pajkrt,1 Martijn A Oudijk1 1Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, the Netherlands; 2The Robinson Research Institute, School for Reproductive Health and Pediatrics, University of Adelaide, Adelaide, SA, Australia Abstract: Preterm birth (PTB), defined as delivery at