High Blood Pressure & Birth Control Pills: What You Should Know

‍Estrogen-containing birth control pills are associated with an increased risk of high blood pressure (hypertension). This risk can further be heightened by pre-existing health conditions and lifestyle choices, like a poor diet or smoking.   

This article discusses high blood pressure, its causes, and the relationship between high blood pressure and estrogen. Keep reading to learn about birth control alternatives that you may use if you are at risk of high blood pressure.  

What is high blood pressure? 

Blood pressure is a term used to describe the force of blood against the walls of your blood vessels. Two measurements are used to assess blood pressure: systolic and diastolic. 

Systolic blood pressure refers to the pressure that occurs when the heart contracts and pushes blood through the blood vessels. Diastolic blood pressure, on the other hand, is the pressure that occurs when the heart relaxes between its heartbeats.  

High blood pressure — also called hypertension — occurs when a person’s systolic and/or diastolic blood pressure stays at high levels throughout the day. 

In Canada, hypertension is defined as systolic blood pressure higher than 140mmHg or diastolic blood pressure higher than 90mmHg. If blood pressure is measured at home, these numbers are 135mmHg or higher for systolic and 85mmHg or higher for diastolic.   

For people with diabetes or chronic kidney disease, blood pressure 130mmHg or higher for systolic and 80mmHg or higher for diastolic is considered hypertension.  

Causes of high blood pressure 

High blood pressure can be caused by many factors, including ones that you can control and those that cannot. 

The causes of high blood pressure can include:

• Age and gender 
• Poor diet 
• Inadequate exercise 
• Smoking tobacco/nicotine products 

In addition to these potential causes, women face a high risk of developing hypertension due to pregnancy, birth control, or menopause. Women who are 65 or older are also considered to be at higher risk of developing high blood pressure than men of the same age.  

High blood pressure can also lead to more serious health conditions like heart disease and stroke.  

High blood pressure and birth control 

The Heart and Stroke Foundation of Canada states that women on birth control pills containing estrogen and progesterone are at a higher risk of developing high blood pressure.

This heightened risk only affects a small portion of women, but it is essential for anyone considering starting this prescription.

Additional factors that can increase this risk further include:

• Smoking 
• Pre-existing hypertension 
• Age greater than 35 
• Migraines with aura (aura refers to visual disturbances that occur temporarily before or during a migraine, such as coloured spots or blurred vision) 
• Blood clotting problems 
• Pre-existing risk factors for heart disease or stroke 

How the pill can affect your blood pressure 

Not all women will experience high blood pressure as a result of taking birth control pills. The occurrence of hypertension due to birth control pills largely depends on the concentration of estrogen. One study found that hypertension occurred in roughly 5% of users taking high-dose birth control pills that contained at least 50 μg estrogen and 1 to 4 mg progestin.  

In general, the pill is considered safe for most women. High-dose pills containing estrogen require regular medical checkups and should be avoided by women with pre-existing risk factors for hypertension.  

Can birth control cause high blood pressure?  

The relationship between estrogen-containing birth control pills and high blood pressure is still largely uncertain in medical and scientific communities.  

As mentioned above, research suggests that high-dose pills containing estrogen may lead to a higher risk for the development of hypertension. However, birth control pills often only increase the risk in women with other risk factors, making it difficult to define the pill as the sole cause of hypertension. 

Instead, birth control pills can be considered an additional risk factor for high blood pressure.  

Birth control options for women with high blood pressure 

Women with high blood pressure or those already at risk of developing the condition should avoid estrogen-containing birth control pills.  

However, several alternative birth control options are available for women at risk of hypertension.  

Sex & U — an initiative of the Society of Obstetricians and Gynaecologists' of Canada — lists the following hormonal contraception and non-hormonal contraception options as available in Canada:  

Intrauterine devices (IUDs)  

Intrauterine devices (IUDs) can be either hormone-containing or not. They both work similarly to thicken cervical mucous and change the uterine lining to prevent pregnancy from occurring. Both are 99% effective in preventing pregnancy.

It is a T-shaped device inserted into the uterus by a healthcare practitioner and can remain there for five to ten years.  

Some side effects of IUDs include irregular bleeding or spotting when not on your period and increased menstrual bleeding or cramping.  

Birth control implants  

Birth control implants are a relatively new option in Canada, as these devices were recently approved in 2020.  

Implants are inserted into a person’s upper arm by a healthcare practitioner and contain a synthetic mix of the hormones progesterone and etonogestrel. They do not contain estrogen.  

After being inserted, an implant can last for up to three years, and the effects are reversible upon removal. These implants can make periods lighter or stop them altogether while in the body. The effectiveness of birth control implants is 99%, with both typical and perfect use.  

Condoms  

Condoms are a non-hormonal barrier contraception method in two primary forms — male external condoms and female internal condoms. 

Male external condoms can be made from either latex or non-latex materials and are worn on an erect penis during sexual intercourse. The effectiveness of male condoms is 92% with typical use or 98% with perfect use.  

Female internal condoms are made from polyurethane and are inserted into the vagina before sexual intercourse. The effectiveness of female condoms is 79% with typical use or 95% with perfect use. 

The added advantage of condoms is that they protect against sexually transmitted diseases and infections. Using condoms is often recommended in tandem with other birth control methods.  

Cervical caps  

A cervical cap is made from silicone and is non-hormonal. It is inserted inside the vagina and must be left in place for around six to eight hours following sexual intercourse.

Cervical caps work by blocking the entryway into the cervix, preventing sperm from reaching an egg.  

No current data is available to assess cervical caps' effectiveness in Canada.  

Cervical caps are often used in tandem with a spermicide gel.  

Diaphragms 

Diaphragms are similar to cervical caps, except they are larger, can be made from silicone or latex, and include a flexible steel ring around the edge.  

Like cervical caps, diaphragms work by preventing sperm from entering the cervix.  

Though generally thought to be more effective than cervical caps, there is not enough data to determine the effectiveness of diaphragms currently in Canada.

Diaphragms are also often used in tandem with a spermicide gel.  

The mini-pill 

The mini-pill is a type of birth control pill that does not contain estrogen.  

Instead, a mini-pill pack contains 28-pill packs of progestin-only pills. These pills must be taken at the same time every day for best use, and the effectiveness is 91% with typical use or 99.7% with perfect use.   

The mini-pill acts to:

1. Inhibit the release of an egg
2. Thicken cervical mucus makes it more difficult for sperm to reach an egg 
3. Thin the lining of the uterus, making it more difficult for an egg to be implanted 

When taking the mini-pill, you may experience a reduced menstrual flow, less intense cramping, and reduced premenstrual symptoms. These pills are taken continuously with no hormone-free intervals.  

Sterilization  

Female sterilization — often referred to as having your “tubes tied” — is a surgical procedure called tubal ligation surgery. It is available to anyone over 18 with approval from a healthcare practitioner. 

Closing of the tubes can be achieved by a healthcare practitioner in a few different ways, including:

• Banding 
• Cauterizing 
• Tying and Cutting 
• Clipping 
• Complete removal of the fallopian tubes 

After the tubes have been closed, eggs can no longer move through them to become fertilized.  

In some rare cases, pregnancy can still happen following this surgery. Approximately 5 out of every 1,000 women become pregnant one year after the surgery. Pregnancy can occur due to the tubes growing back together or if the surgery is done incorrectly.  

Key takeaways 

If you are at high-risk for hypertension,  estrogen-containing birth control pills may not be the best choice, but there are many birth control alternatives for women who want to use contraception.  

 Get started with Felix today to discuss what birth control options may be right for you.