Women with pregnancy induced hypertension have a higher risk of developing essential hypertension - a case control study from a tertiary care center in Pakistan

Objectives: To determine the association of essential hypertension with pregnancy-induced hypertension in women. Methods: The case-control study was conducted at Aga Khan University Hospital, Karachi, from January 2012 to March 2013, and comprised on hypertensive female patients who visited the outpatient medicine clinics. The patients were aged 18-65 years and had been pregnant atleast once. Cases were women diagnosed as hypertensive or pre-hypertensive and the controls were normotensive women. The primary outcome was essential hypertension and the main exposure was pregnancy-induced hypertension. Results: Of the 258 subjects, 175(49.7%) were cases and 177(50.3%) were controls. The overall mean age was 44.6 +/- 13.3 years. Odds Ratio (95% Confidence interval) for pregnancy-induced hypertension for the outcome of essential hypertension was 1.6 (0.88, 3.0). The odds ratio increased further to 2.5(1.2, 5.2) after adjustment for age, family history of hypertension and physical activity. The association remained after further adjusting for body mass index in the final model; 2.20 (1.06, 4.57) Conclusion: Women who develop hypertension in pregnancy are at higher risk of developing essential hypertension later in life.