Dystocia is a serious problem for pregnant women,and it increases the cesarean section rate.Although uterine dysfunction has an unknown etiology,it is responsible for cesarean delivery and clinical dystocia,resulting in neonatal morbidity and mortality;thus,there is an urgent need for novel therapeutic agents.Previous studies indicated that statins,which inhibit the mevalonate(MVA) pathway of cholesterol synthesis,can reduce the incidence of preterm birth,but the safety of statins for pregnant women has not been thoroughly evaluated.Therefore,to unambiguously examine the function of the MVA pathway in pregnancy and de-livery,we employed a genetic approach by using myometfial cell-specific deletion of geranylgeronyl pyrophosphote synthose(Ggps1) mice.We found that Ggps1 deficiency in myometrial cells caused impaired uterine contractions,resulting in disrupted embryonic placing and dystocia.Studies of the underlying mechanism suggested that Ggps1 is required for uterine contractions to ensure successful parturition by regulating RhoA prenylation to activate the RhoA/Rock2/p-MLC pathway.Our work indicates that perturbing the MVA pathway might result in problems during delivery for pregnant females,but modifying protein prenylation with supplementary farnesyl pyrophosphate or geranylgeranyl pyrophosphate might be a strategy to avoid side effects.