The cause of gestational hypertension is unclear, but it is believed that
this entity occurs in women destined to have essentialhy pertension later
in life (analogous to women with gestational hyperglycaemia who eventually
develop type 2 diabetes). A significant proportion of patients with
gestational hypertension may represent an early phase of pre-eclampsia
in which proteinuria has not yet appeared. Renal biopsy studies support
the latter hypothesis.12