PROK1 and polycystic ovary syndrome: The relatively hypoxic milieu in the abnormal placenta leads to the upregulation of several hypoxia-regulated factors, among others PROK1.10 Dysregulation of PROK1 is associated with preeclampsia, IUGR and preterm delivery.13–16 We have previously shown that insulin upregulates PROK1 in decidualising endometrial stromal cells in vitro, and androgens potentiate this enhancement.17 18 Despite hyperinsulinaemia/hyperandrogenism and an increased occurrence of these pregnancy complications, the role of PROK1 has not been studied in PCOS.