Blood pressure and renal function seven years after pregnancy complicated by hypertension.

OBJECTIVE: To assess the occurrence of chronic hypertension and renal disorder after gestations complicated by pregnancy induced hypertension or pre-eclampsia and to define background factors and laboratory analyses at follow up examination which discriminate between women who remain normotensive and those who develop hypertension.
SETTING: Swedish university hospital.
SUBJECTS: Women with pregnancy induced hypertension (PIH) (n = 49), pre-eclampsia (n = 45) or a normotensive pregnancy (n = 44) during 1986.
DESIGN: Subjects were reviewed in 1993 with regard to chronic hypertension and renal disorder. Plasma concentrations of creatinine, urea, uric acid, calcium and albumin were measured, and urine was examined for the presence of microalbuminuria and erythrocyte excretion rate. Those with and without hypertension at follow up were compared with regard to the renal function tests and possible features in the history which might predict chronic hypertension.
RESULTS: Women with a history of pregnancy induced hypertension or pre-eclampsia had an increased risk, relative to controls, for hypertension at follow up (37% and 20% vs 2%; P < 0.001), microalbuminuria (14% and 20% vs 2%; P < 0.05) and demonstrated increased plasma levels of albumin corrected calcium (2.41 [SE 0.02] and 2.40 [0.01] vs 2.32 [0.01] mmol/l; P < 0.001). The only factors significantly associated with hypertension at follow up were the presence of microalbuminuria (P = 0.0008) and having had a delivery prior to the index pregnancy (P = 0.0017).
CONCLUSIONS: The risk for chronic hypertension seven years after a pregnancy complicated with pregnancy induced hypertension or pre-eclampsia is considerably increased. The presence of hypertension at follow up is closely related to residual renal disorder.