High blood pressure (hypertension) complicates contraceptive choice. Whether birth control can be used depends heavily on the specific method and the severity of the elevated blood pressure. Since certain hormonal methods increase cardiovascular risk, consulting a healthcare provider is essential to determine the safest option.
How Hormones Influence Blood Pressure
Combined hormonal contraceptives (CHCs), containing both estrogen and progestin, are most associated with increased blood pressure. Estrogen is the primary culprit, stimulating the liver to produce more angiotensinogen. This protein activates the Renin-Angiotensin-Aldosterone System (RAAS), which regulates blood pressure and fluid balance. Activation of the RAAS narrows blood vessels and increases sodium and water retention, thus elevating blood pressure.
Progestin-only methods do not contain estrogen and do not activate the RAAS in the same way. This difference explains why progestin-only methods pose a lower risk of blood pressure elevation compared to combined pills, patches, or rings.
Medical Criteria for Contraceptive Use
Medical professionals use specific criteria based on blood pressure readings to determine contraceptive safety. For individuals with mild, well-controlled hypertension (systolic 140–159 mmHg or diastolic 90–99 mmHg), combined hormonal contraceptives (CHCs) are generally not recommended. The risks of stroke and heart attack usually outweigh the benefits of using an estrogen-containing method in this group.
A healthcare provider might cautiously consider a trial of a low-dose combined method for women under 35 with adequately controlled mild hypertension if other options are unacceptable. CHCs are contraindicated for anyone with severe hypertension (systolic 160 mmHg or higher or diastolic 100 mmHg or higher). Using CHCs in this setting increases the risk of cardiovascular events.
Safe Contraception Options for Hypertension
For women with hypertension, several effective contraceptive options avoid the risks associated with estrogen. Progestin-only methods are the first-line hormonal choice because they do not contain estrogen and do not significantly affect blood pressure. These options include the Progestin-Only Pill (POP), the contraceptive implant, and the hormonal intrauterine device (IUD).
The hormonal IUD and the implant are beneficial because they offer long-acting, reversible contraception and deliver progestin locally or in a low systemic dose. Non-hormonal methods are the safest category, as they have no impact on the circulatory system. The copper IUD and barrier methods, such as condoms and diaphragms, are excellent choices for individuals with any degree of hypertension.
Necessary Monitoring and Follow-Up
Before starting any hormonal contraceptive, especially a combined one, a baseline blood pressure measurement is mandatory to screen for hypertension. This initial check identifies individuals who should avoid estrogen-containing products.
If a combined hormonal contraceptive is prescribed, close follow-up is necessary to monitor for adverse changes. Blood pressure should be rechecked within 2 to 4 weeks, or at least within three months, of starting the method. If a significant and persistent elevation occurs, the combined method must be discontinued promptly. The blood pressure elevation caused by CHCs is usually reversible, with readings often returning to pre-treatment levels within a few months of stopping the medication.