A method of detecting a risk of a pregnant female mammal developing pre-eclampsia or a complication linked thereto, or of a fetus of the pregnant female mammal developing a fetal or neonatal deficiency linked to maternal pre-eclampsia, comprises detecting the level of a VEGFxxxb in a sample from the pregnant female mammal at less than about 24 weeks of gestation and comparing the detected level with a reference level. A reduced level in the sample from the pregnant female mammal is indicative of a risk of the pregnant female mammal developing pre-eclampsia or a complication linked thereto or of the fetus developing the fetal or neonatal deficiency linked to maternal pre-eclampsia.