Preterm birth is the most common cause of neonatal death in New Zealand. Infants who survive preterm delivery have low birth weight and are more likely to suffer chronic illness as adults. Hence, it is important to understand the fundamental mechanisms that control normal labour and milk production. The hormone, oxytocin, is secreted from the brain to contract the uterus for delivery of the baby, and premature oxytocin cell activation contributes to preterm delivery. We have shown that a newly identified hormone, kisspeptin, excites oxytocin-secreting cells. The human placenta secretes large amounts of kisspeptin, particularly during the third trimester. We will record oxytocin cell activity during pregnancy to determine whether placental kisspeptin normally drives the increased activity of oxytocin cells during delivery. By determining whether kisspeptin excitation of oxytocin cells underpins normal delivery, we hope to develop strategies to prevent preterm delivery in women.