KISS1 and preeclampsia: Furthermore, the levels of serum kisspeptin in early pregnancy are associated with intra-uterine growth restriction, recurrent pregnancy loss and preeclampsia [19], [20].In addition, quantitative polymerase chain reactions (PCR) and in situ hybridization analysis indicated that both Kiss1 and GPR54 mRNA were expressed in rat uterus and placenta [21].