There is a growing interest in the role of antimicrobial peptides (AMPs) in the female reproductive tract during pregnancy. This commentary highlights recent advances in the field including those of Itakoa and colleagues who have demonstrated elafin and secretory leukocyte protease inhibitor (SLPI) expression in cervical cells from pregnant women during pregnancy. They suggest that these specific AMPs may be raised in women in true preterm labour. This complements other studies exploring the use cervico-vaginal fluid elafin and other antimicrobial peptides as biomarkers to predict risk of spontaneous preterm birth early in pregnancy. With continued focus on the contribution and regulation of these important small peptides in pregnancy, the potential of AMPs as clinical tools for identifying women most at risk of spontaneous preterm birth should soon be realised.