High Blood Pressure During Pregnancy
September 5, 2024 No Comments
If you’re pregnant or trying to conceive, your OB/GYN may have talked to you about preeclampsia, a common pregnancy complication. Preeclampsia is a blood pressure disorder which happens during pregnancy and is more severe than gestational high blood pressure, but not as severe as eclampsia (seizures in pregnancy). It involves dysfunction in your blood vessels and, in some instances, can lead to organ failure.
A lot of people associate high blood pressure as something you deal with when you’re older, but it turns out, many pregnant women have to deal with it too.
High blood pressure in pregnancy is incredibly common, occurring in 10% of all pregnancies!
A new study showed that rates of pregnancy-induced hypertension (PIH) have doubled in recent years—the study indicated that rates of pregnancy-induced hypertension rose from 1.8% in 2008 to 3.7% in 2021.
The findings are consistent with other recent studies, which show a sharp increase in the risk for high blood pressure among millennial and Gen Z patients compared to Baby Boomers. What is going on here and why is the risk of developing high blood pressure, especially during pregnancy when the risks are much greater, increasing so dramatically in recent years?
In this blog post, we’ll dive into the different types of high blood pressure during pregnancy, causes of high blood pressure during pregnancy, how high blood pressure can affect pregnancy, risk factors for preeclampsia, and how to naturally lower blood pressure when pregnant.
Sometimes high blood pressure begins before pregnancy. In other cases, the condition develops during pregnancy.
In chronic hypertension, high blood pressure develops either before pregnancy or during the first 20 weeks of pregnancy. Because high blood pressure usually doesn’t have symptoms, it might be hard to know exactly when it began.
This condition occurs when chronic hypertension leads to worsening high blood pressure during pregnancy. People with this condition may develop protein in the urine or other complications.
People with gestational hypertension have high blood pressure that develops after 20 weeks of pregnancy. There’s no excess protein in the urine and there are no other signs of organ damage. But in some cases, gestational hypertension can eventually lead to preeclampsia.
Preeclampsia occurs when hypertension develops after 20 weeks of pregnancy. Preeclampsia is a gestational hypertensive disorder that is more severe than gestational high blood pressure, but not as severe as eclampsia (seizures in pregnancy). It involves dysfunction in your blood vessels and, in some instances, can lead to organ failure.
Experts are not 100% clear on the cause of high blood pressure during pregnancy, but there is evidence that it starts with abnormal placental development in the first and second trimesters.
Genetic factors, comorbidities, an altered immune response, and an increase in oxidative stress are all possible contributors to abnormal placental development. This creates a perfect storm for preeclampsia to develop in the third trimester, when symptoms of high blood pressure and protein in the urine become evident.
Additionally:
A common question, with a complicated answer: yes and no.
In some cases, high blood pressure and preeclampsia can be managed with lifestyle choices; however, there are many risk factors for preeclampsia that may not be entirely in your control:
If untreated, gestational hypertension can be dangerous, increasing the risk of the following complications:
If the placenta doesn’t get enough blood, the fetus might receive less oxygen and fewer nutrients. This can lead to slow growth (intrauterine growth restriction), low birth weight or premature birth. Babies born early can have breathing problems, increased risk of infection and other complications.
In this condition, the placenta separates from the inner wall of the uterus before delivery. Preeclampsia and high blood pressure increase the risk of placental abruption. Severe abruption can cause heavy bleeding, which can be life-threatening for you and your baby.
High blood pressure might result in slowed or decreased fetal growth.
Poorly controlled high blood pressure can result in injury to the brain, eyes, heart, lungs, kidneys, liver, and other major organs. In severe cases, it can be life-threatening.
Sometimes an early delivery is needed to prevent life-threatening complications from high blood pressure during pregnancy.
Having preeclampsia might increase your risk of future heart and blood vessel (cardiovascular) disease. The risk of future cardiovascular disease is higher if you’ve had preeclampsia more than once. It’s also higher if you’ve had a premature birth due to having high blood pressure during pregnancy.
Monitoring your blood pressure is an important part of prenatal care. If you have chronic hypertension, your health care provider will consider these categories for blood pressure measurements:
Elevated blood pressure is a systolic pressure ranging from 120 to 129 millimeters of mercury (mm Hg) and a diastolic pressure below 80 mm Hg. Elevated blood pressure tends to get worse over time unless steps are taken to control it.
Stage 1 hypertension is a systolic pressure ranging from 130 to 139 mm Hg or a diastolic pressure ranging from 80 to 89 mm Hg.
Stage 2 hypertension is more severe—it’s a systolic pressure of 140 mm Hg or higher or a diastolic pressure of 90 mm Hg or higher.
After 20 weeks of pregnancy, blood pressure that’s higher than 140/90 mm Hg without any other organ damage is considered to be gestational hypertension. Blood pressure needs to be taken and documented on two or more occasions, at least four hours apart.
To diagnose preeclampsia your doctor will look for high blood pressure (systolic blood pressure ≥140 mm Hg or diastolic blood pressure of ≥90 mm Hg, or both) plus evidence of protein in your urine (proteinuria).
Symptoms of preeclampsia include, but are not limited to:
Sudden weight gain and swelling—particularly in the face and hands—often occurs with preeclampsia. The swelling associated with preeclampsia is more severe than the typical swelling that happens during pregnancy.
Most preeclampsia resolves once your baby is delivered, but it can persist after birth. Postpartum preeclampsia is one of the most common causes of readmission to the hospital following birth, affecting ~1% of all deliveries. The American Journal of Obstetrics and Gynecology recommends screening for it starting 48 hours after delivery, and up to 6 weeks after delivery.
Some blood pressure medications are considered safe to use during pregnancy. However, angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers and renin inhibitors need to be avoided during pregnancy.
Treatment is important. High blood pressure increases your risk of heart attack and stroke, among other major complications. And, as we know, high blood pressure can be dangerous for your baby.
If you need medication to control your blood pressure during pregnancy, your health care provider will prescribe the safest medication and dose. Take the medication exactly as prescribed. Don’t stop taking it or change the dose on your own.
Low-dose daily aspirin is often recommended to lower the risk of preeclampsia in those who are at high risk. Studies have found low-dose aspirin to be safe during pregnancy.
If you were diagnosed with gestational hypertension or are at risk of developing it during pregnancy, it’s important to find ways to keep your blood pressure under control; and since a lot of hypertension medications are not recommended during pregnancy, the key to doing so is making important diet and lifestyle changes.
For preeclampsia specifically, low protein intake (<65 g/day) has been associated with an increased risk for preeclampsia and eclampsia (seizures during pregnancy).
In addition to adequate protein intake, it’s important to consume specific amino acids—preeclampsia is a disorder that impacts the blood vessels, so having adequate ability for blood vessels to expand and contract is important for blood pressure regulation.
The amino acid glycine helps in the production of elastin, which allows for blood vessel flexibility. It also protects against oxidative stress by reducing free radicals, further supporting blood vessels.
Include plenty of glycine-rich foods in your daily diet:
Read more here: How much protein do pregnant women need?
Minerals like sodium (found in salt), calcium, magnesium, and potassium are all critical for preeclampsia mitigation. Studies show that a low-salt diet neither prevents nor treats preeclampsia—in fact, it can actually make it worse!
Although conventional guidelines recommend reducing salt intake to lower blood pressure in general, pregnancy-induced high blood pressure seems especially non-responsive to salt restriction.
The trick is making sure that the salt you are using at home is unrefined, mineral-rich salt such as Celtic Sea Salt, Himalayan Salt, Utah Real Salt, and other sources of unrefined/unprocessed salt. No Kosher salt or white table salt!
While adequate sodium is important in pregnancy, it should be consumed hand-in-hand with potassium. A study that assessed urine analysis of sodium and potassium levels in pregnant women at the beginning of the third trimester found that women with preeclampsia had a higher ratio of sodium to potassium … meaning that a diet rich in sodium without enough potassium may lead to poor pregnancy outcomes.
In other words:
A diet of whole, nutrient-dense foods (with ample potassium) that is salted-to-taste (with mineral-rich, unrefined salt!) is a good idea.
A diet of processed foods that’s very salty (but lacking in potassium) is not a good idea.
Make sure to include plenty of potassium-rich foods like bananas, sweet potatoes, avocados, dark leafy greens, prunes, raisins, kidney beans, and tomatoes in your daily diet.
Women with preeclampsia tend to have lower intakes of calcium and magnesium. To mitigate this, calcium supplements are often recommended to women with preeclampsia.
A 2018 study suggested that a high-dose supplement of calcium (>1000 mg/day) reduces the risk of high blood pressure and preeclampsia in pregnancy, especially in women with a low-calcium diet.
As a nutritionist, I believe in food first. Calcium-rich foods include:
If you are unable to obtain adequate amounts of calcium through diet alone, using a high quality calcium supplement can be helpful.
Low magnesium levels have been associated with a significantly higher risk of preeclampsia at both mid-pregnancy and term.
Food sources of magnesium include:
If you are unable to obtain adequate amounts of calcium through diet alone, using a high quality magnesium supplement can be helpful.
Vegetables and fruit are some of our best sources of potassium, namely: green leafy vegetables, tomatoes, bananas, Brussels sprouts, mushrooms, winter squash, avocados, citrus fruit, and broccoli.
In addition, fresh produce—especially colorful fruits and vegetables—are rich in antioxidants. Since preeclampsia likely stems from an increase in oxidative stress, antioxidants help to counterbalance this.
While all fruits and vegetables provide some level of antioxidants, berries are especially high in them. Studies suggest consuming berries (particularly blueberries) may help to lower your blood pressure. Plus, the fiber in berries and other produce (especially non-starchy vegetables) can help keep blood sugar in a healthy range by slowing the absorption of carbohydrates from your digestive system.
Choline is a micronutrient found in greatest concentrations in organ meats, egg yolks, meat and seafood that plays a big role in placental function. Choline is significant because it may actually enhance the transfer of nutrients to your baby, a process that can be disrupted in preeclampsia.
Studies that supplemented choline during pregnancy resulted in prevention of preeclampsia, reduced placental inflammation, and improved vascular placental function. In fact, up to 930 mg of choline per day may be beneficial–which is more than DOUBLE that of the current recommendations.
Did you know that high blood sugar and high blood pressure go hand in hand?
If a woman has insulin resistance in her first trimester, this may actually predict preeclampsia later in the pregnancy. This could explain why the development of preeclampsia is more common among women with blood sugar imbalances (like gestational diabetes).
Even without any diagnosable blood sugar issues, a high intake of refined carbohydrates in pregnancy is a risk factor for preeclampsia. A study of nearly 33,000 pregnant women found those who ate the most added sugars (ultra-processed foods) were more likely to develop preeclampsia.
The good news:
By choosing high-quality whole food sources of carbohydrates and consuming them alongside foods that contain protein, fat, and fiber, you’re much more likely to have steady, balanced blood sugar levels. Think whole non-gluten containing grains such as: quinoa, amaranth, buckwheat, gluten free-certified oats and rice; starchy root vegetables like sweet potatoes, plantains, winter squashes, yucca; as well as properly prepared lentils and beans.
In some cases, high blood pressure can be a sign of dehydration. Pregnancy requires increased water intake, so aim to get at least half your body weight in ounces of clean, filtered water daily (not exceeding 100 ounces). Herbal teas, bone broth, coconut water, and high-water content fruit all count toward your water goal, too.
Whether you are pregnant or not, being stressed can actually cause your blood pressure to spike. Identify the things that trigger anxiety, and do what you can to avoid these things as much as you can. Also do what you can to promote relaxation—whether it’s meditation, yoga, walks in nature, or breathwork. These practices can help alleviate anxiety, promote relaxation, lower blood pressure, AND can help you manage labor pain on the big day ;).
Implementing a consistent physical routine that you can do throughout your pregnancy is very important. Not only will it relieve stress, increase blood circulation, and lower blood pressure, but it will have a positive impact on your baby’s health outcome going forward. Get at least 30-45 minutes of movement every single day. If you don’t usually work out, you can do things that are not too intensive, like walking, hiking or swimming.
Read more here: Exercising During Pregnancy: The Good, Bad, and the Ugly and 7 Exercises to Optimize Your Body for Birth.
This should go without saying, but avoiding smoking and alcohol during your pregnancy is essential for the safety and health of your baby. What’s more, both alcohol and cigarette smoking can bring your blood pressure up. So if you are still smoking during pregnancy, find the help you need to implement a plan to quit asap.
If you’ve been advised to take any medications, it’s important to adhere to the schedule and take it as noted. In some cases, your doctor may recommend a low-dose aspirin or a hypertension medication that’s shown to be safe in pregnancy. Also, hypertension can be a side effect of some medication. Make sure to talk to your doctor to find out what is safe to take during pregnancy.
If you’re experiencing high blood pressure during pregnancy, remember that small lifestyle and dietary changes can make a big difference in managing your blood pressure levels.
Preeclampsia may not be a pregnancy outcome we can avoid altogether, but by incorporating the following nutrition suggestions, you can potentially reduce the risk of developing it (or lessen the severity of preeclampsia, if you do develop it):
– Focus on eating real, whole foods during pregnancy.
– Choose an abundance of colorful fruits and vegetables high in antioxidants to reduce oxidative stress.
– Prioritize protein intake, especially foods with glycine, to support blood vessel flexibility.
– Incorporate liver, eggs, or other food sources high in choline to support placental transfer of nutrients to the baby.
– Maintain your minerals by getting enough sodium, calcium, magnesium, and potassium.
– Choose high-quality, unprocessed carbohydrates and reduce your intake of refined carbohydrates and added sugar.
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Sarah Jane Sandy is a certified nutrition therapist, and a fertility and women’s health expert. She has helped hundreds of women increase their fertility naturally and go on to have healthy full-term pregnancies. She has been working with women and couples trying to get pregnant for over 16 years and over 90% of the women who work with her get pregnant and have healthy babies.
She also works with women trying to fix their hormone imbalances, as well as supporting women through pregnancy and the postpartum period. Learn more about her own fertility and hormone journey here. To send Sarah a message, complete her Contact Form.
