Stopping oral contraceptives: an effective blood pressure-lowering intervention in women with hypertension.

The association of combined oral contraceptives (OC) with higher blood pressure (BP) may be attenuated with pills with smaller doses of oestrogen. The effect of stopping OC on BP of patients with hypertension was not described to date. In a cohort study of patients with hypertension, we identified 72 women using OC among 2112 patients seen from 1989 to 2002. Stopping hormonal contraception was recommended to all. The main outcome measurement was BP change in women who stopped (n=44) and who did not stop (n=28) OC, adjusting for baseline BP and age. Odds ratio for having a reduction of at least 20 mmHg in systolic blood pressure (SBP) or 10 mmHg in diastolic blood pressure (DBP), adjusting for age, change in weight and prescription of BP-lowering drugs, were calculated. The mean follow-up time was 6.6+/-7.5 months. Participants who stopped and did not stop OC had similar baseline characteristics. The deltas of SBP (adjusted) were 15.1+/-2.6 mmHg in patients who stopped and 2.8+/-3.2 mmHg in patients who did not stop OC (P=0.004). The corresponding values for DBP were 10.4+/-1.8 and 2.7+/-2.2 mmHg (P=0.008), respectively. The odds ratio (adjusted) for having a decrease of at least 20 mmHg in SBP or 10 mmHg in DBP was 0.28 (95% CI 0.08-0.90) in patients who stopped OC. Stopping OC is an effective antihypertensive intervention in a clinical setting.