Full Stage Lay Summary The aim of this project is to understand the fundamental biological processes that control pregnancy. Problem pregnancies, particularly preterm delivery, risk death for the baby, and those babies who survive are more likely to suffer chronic illness as adults. The hormone, oxytocin, is secreted from the brain to contract the uterus for delivery of the baby. Inappropriate oxytocin secretion contributes to problem pregnancies, including preterm delivery. We have discovered that central administration of a newly-identified neuropeptide, kisspeptin, excites oxytocin-secreting cells only in late pregnancy. However, the impact of this excitation on pregnancy remains to be determined. We will genetically manipulate kisspeptin receptors on oxytocin cells in mice to determine whether central kisspeptin excitation of oxytocin cells is required for successful delivery. This work will increase our knowledge of the biological processes required for normal pregnancy and underpin the development of alternative strategies to manage problem pregnancies.