The present invention relates to the biological and pharmacological effects of placental protein 13 (PP-13), an effect that may be used as a treatment and/or prevention of preeclampsia and placental insufficiencies, in pregnant female mammals, especially pregnant women. The invention relates to a method to treat female mammals with the purpose to precondition the uterine arteries and prevent and/or reverse the pathological conditions associated with placental insufficiency such as preeclampsia, HELLP and/or eclampsia.