PTH and preeclampsia: The aims of this study are therefore to (a) determine whether maternal circulating 25(OH)D, PTH and calcium concentrations are associated with gestational hypertension and pre-eclampsia and associated adverse perinatal outcomes (caesarean section, preterm birth and small for gestational age) in White British and Pakistani women, and (b) establish whether the magnitude or direction of associations between 25(OH)D, PTH and calcium with these outcomes differ between White British and Pakistani women.