High Blood Pressure in Pregnancy
Blood pressure is the force of your blood pushing against the walls of your arteries as your heart pumps blood. High blood pressure, or hypertension, is when this force against your artery walls is too high.
There are different types of high blood pressure in pregnancy:
- Gestational hypertension:
It is high blood pressure that you develop while you are pregnant. It starts after you are 20 weeks pregnant. You usually don’t have any other symptoms. In many cases, it does not harm you or your baby, and it goes away within 12 weeks after childbirth. But it does raise your risk of high blood pressure in the future. It sometimes can be severe, which may lead to low birth weight or preterm birth. Some women with gestational hypertension do go on to develop preeclampsia.
- Chronic hypertension:
Is high blood pressure that started before the 20th week of pregnancy or before you became pregnant. Some women may have had it long before becoming pregnant but didn’t know it until they got their blood pressure checked at their prenatal visit. Sometimes chronic hypertension can also lead to preeclampsia.
- Preeclampsia:
This is a sudden increase in blood pressure after the 20th week of pregnancy. It usually happens in the last trimester. In rare cases, symptoms may not start until after delivery. This is called postpartum preeclampsia. Preeclampsia also includes signs of damage to some of your organs, such as your liver or kidney. The signs may include protein in the urine and very high blood pressure. Preeclampsia can be serious or even life-threatening for both you and your baby.
Preeclampsia Causes
The cause of preeclampsia is not known.
Who is at risk for preeclampsia?
You are at higher risk of preeclampsia if you
- Had chronic high blood pressure or chronic kidney disease before pregnancy
- Had high blood pressure or preeclampsia in a previous pregnancy
- Have obesity
- Are over age 40
- Are pregnant with more than one baby
- Are African American
- Have a family history of preeclampsia
- Have certain health conditions, such as diabetes, lupus, or thrombophilia (a disorder which raises your risk of blood clots)
- Used in vitro fertilization, egg donation, or donor insemination
What problems can preeclampsia cause?
Preeclampsia can cause
- Placental abruption, where the placenta separates from the uterus
- Poor fetal growth, caused by a lack of nutrients and oxygen
- Preterm birth
- A low birth weight baby
- Stillbirth
- Damage to your kidneys, liver, brain, and other organ and blood systems
- A higher risk of heart disease for you
- Eclampsia, which happens when preeclampsia is severe enough to affect brain function, causing seizures or coma
- HELLP syndrome, which happens when a woman with preeclampsia or eclampsia has damage to the liver and blood cells. It is rare but very serious.
Symptoms of Preeclampsia
Possible symptoms of preeclampsia include
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- High blood pressure
- Too much protein in your urine (called proteinuria)
- Swelling in your face and hands. Your feet may also swell, but many women have swollen feet during pregnancy. So swollen feet by themselves may not be a sign of a problem.
- Headache that does not go away
- Vision problems, including blurred vision or seeing spots
- Pain in your upper right abdomen
- Trouble breathing
Eclampsia can also cause seizures, nausea and/or vomiting, and low urine output. If you go on to develop HELLP syndrome, you may also have bleeding or bruising easily, extreme fatigue, and liver failure.
Preeclampsia Diagnosis
Your health care provider will check your blood pressure and urine at each prenatal visit. If your blood pressure reading is high (140/90 or higher), especially after the 20th week of pregnancy, your provider will likely want to run some tests. They may include blood tests other lab tests to look for extra protein in the urine as well as other symptoms.
Preeclampsia Treatment
Delivering the baby can often cure preeclampsia. When deciding on treatment, your provider takes into account several factors. They include how severe it is, how many weeks pregnant you are, and what the potential risks to you and your baby are:
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- If you are more than 37 weeks pregnant, your provider will likely want to deliver the baby.
- If you are less than 37 weeks pregnant, your health care provider will closely monitor you and your baby. This includes blood and urine tests for you. Monitoring for the baby often involves ultrasound, heart rate monitoring, and checking on the baby’s growth. You may need to take medicines, to control your blood pressure and to prevent seizures. Some women also get steroid injections, to help the baby’s lungs mature faster. If preeclampsia is severe, your provider may want you to deliver the baby early.
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The symptoms usually go away within 6 weeks of delivery. In rare cases, symptoms may not go away, or they may not start until after delivery (postpartum preeclampsia). This can be very serious, and it needs to be treated right away.
High Blood Pressure in Pregnancy Causes
There are several possible causes of high blood pressure during pregnancy.
These include:
- Being overweight or obese
- Not getting enough physical activity
- Smoking
- Drinking alcohol
- First-time pregnancy
- A family history of pregnancy-related hypertension
- Carrying more than one child
- Age (over 35)
- Assistive reproductive technology (such as in vitro fertilization, or IVF)
- Having diabetes or certain autoimmune diseases
High Blood Pressure in Pregnancy Risks
There are a few risk factors that could make high blood pressure more likely during pregnancy.
Lifestyle
Unhealthy lifestyle choices may lead to high blood pressure during pregnancy. Being overweight or obese, or not staying active are major risk factors for high blood pressure.
Type of pregnancy
Women experiencing their first pregnancy are more likely to have high blood pressure. Fortunately, there’s a lower chance of this condition in subsequent pregnancies.
Carrying multiples can make it more likely for a woman to develop hypertension because the body is working harder to nourish more than one baby.
According to the American Society for Reproductive MedicineTrusted Source, using assistive technologies (such as IVF) during the conception process can increase the chances of high blood pressure in a pregnant woman.
Age
Age can also be a factor. Pregnant women over the age of 35 are at higher risk. Women who had high blood pressure before pregnancy are at higher risk for related complications during pregnancy than those with normal blood pressure.
Tracking High Blood Pressure in Pregnancy
A blood pressure reading is a fraction: your systolic blood pressure over your diastolic blood pressure.
The top number is your systolic pressure, which is a measurement of the pressure on your arteries when the heart is beating or squeezing blood forward through your body.
The diastolic pressure, or the lower number, is a measurement of the blood pressure in your arteries when the heart is at rest.
What is considered normal blood pressure during pregnancy? | What to expect
To determine what your “normal” blood pressure is during pregnancy, your doctor will likely take a baseline blood pressure measurement at your first visit. Then they will measure your blood pressure at every visit that follows.
Normal blood pressure is anything less than 120/80 mm Hg.
What is considered high blood pressure during pregnancy?
A blood pressure that is greater than 130/90 mm Hg or that is 15 degrees higher on the top number from where you started before pregnancy may be cause for concern.
High blood pressure during pregnancy is defined as 140 mm Hg or higher systolic, with diastolic 90 mm Hg or higher.
Early in pregnancy, usually from 5 weeks to the middle of the second trimester, a pregnant woman’s blood pressure may actually decrease. This is because pregnancy hormones can stimulate blood vessels to widen. As a result, the resistance to blood flow isn’t as high.
What is considered low blood pressure during pregnancy?
While there isn’t a definitive number that is too low, there are symptoms that are associated with low blood pressure:
- headache
- dizziness
- nausea
- feeling faint
- cold, clammy skin
High Blood Pressure in Pregnancy Changes
As a woman progresses in her pregnancy, her blood pressure may change or return to pre-pregnancy levels. There are a few possible reasons for this.
The amount of blood in a woman’s body increases. According to the journal Circulation, a woman’s blood volume increases by as much as 45 percent during pregnancy. This is extra blood that the heart must pump throughout the body.
The left ventricle (left side of the heart that does a significant amount of pumping) becomes thicker and larger. This temporary effect allows the heart to work harder to support the increased blood volume.
The kidneys release increased amounts of vasopressin, a hormone that leads to increased water retention.
In most cases, high blood pressure during pregnancy will decrease after the baby is delivered. In cases where blood pressure remains elevated, your doctor may prescribe medication to get it back to normal.
Tips for tracking blood pressure during pregnancy
There are ways to track your blood pressure between doctor visits.
You can buy a blood pressure monitor from a pharmacy or online medical goods store. Many of these devices will go on your wrist or upper arm. To check the monitor’s accuracy, take it to your doctor’s office and compare the readings on the monitor to those from your doctor.
Visit a grocery store, pharmacy, or other stores that have a machine that takes blood pressure readings.
For the most accurate readings, take your blood pressure at the same time every day. Take it while seated with your legs uncrossed. Use the same arm each time.
Notify your doctor immediately if you have repeated high blood pressure readings that are four hours apart or symptoms of high blood pressure.
High Blood Pressure in Pregnancy Complications
If you have high blood pressure during pregnancy, there can be complications that you may incur.
Preeclampsia
This condition can cause serious damage to your organs, including your brain and kidneys. Preeclampsia is also known as toxemia. Preeclampsia with seizures becomes eclampsia. If left untreated, it can be fatal.
Symptoms of preeclampsia include:
- abnormal swelling in hands and face
- persistent headaches
- seeing spots or having changes in vision
- upper abdominal pain
- nausea or vomiting later in pregnancy
- difficulty breathing
Because preeclampsia can be dangerous for both you and your baby, you should call your doctor if you have any of these symptoms.
Keeping regular doctor visits and letting your doctor know about any changes can help them catch and treat preeclampsia early.
HELLP syndrome
HELLP is an acronym that stands for hemolysis, elevated liver enzymes, and low platelet count. This condition is severe and life-threatening and can be a complication of preeclampsia.
Symptoms associated with HELLP include:
- nausea
- vomiting
- headache
- upper abdominal pain
Because HELLP syndrome can severely damage organ systems vital to life, emergency medical care is aimed at reducing blood pressure for the health of the mother and the baby. In some cases, premature delivery is required.
High blood pressure during pregnancy can also have an effect on the baby’s growth rate. This can result in low birth weight. According to the American Congress of Obstetricians and Gynecologists, other complications include:
- placental abruption, a medical emergency during which the placenta detaches from the uterus prematurely
- preterm delivery, defined as delivery prior to 38 weeks of pregnancy
- cesarean delivery, commonly known as C-section
High Blood Pressure in Pregnancy Preventions
Common risk factors for high blood pressure, such as obesity, can be minimized through diet and exercise.
During pregnancy, it’s normal to gain some weight. If you’re concerned, talk to your doctor about a target weight gain and ways to stay within a range that’s healthy for you.
Dietary guidelines for pregnant women vary from person to person. A nutritionist can help create a meal plan that’s designed for your specific height and weight.
Avoid smoking and drinking alcohol. Both are known to raise blood pressure and to cause other complications during pregnancy.
Pregnancy causes hormone shifts as well as psychological and physical changes. This can bring on stress, which can make high blood pressure harder to manage. Try stress-reduction techniques such as yoga and meditation
High Blood Pressure in Pregnancy Medication
Some traditional blood pressure medications can cause problems in pregnant women.
These medications for lowering blood pressure are typically not recommended during pregnancy:
- ACE inhibitors
- Renin-inhibitors
- Angiotensin receptor blockers
These drugs, in particular, will pass through the bloodstream to the baby and negatively impact the developing baby’s health.
Methyldopa and labetalol are both drugs that are considered safe to use to manage blood pressure during pregnancy.
Conclusion
f high blood pressure goes untreated during pregnancy, it can become life-threatening for both mother and baby.
Hypertensive disorders resulting from high blood pressure are the second-leading cause of U.S. maternal death during pregnancy, so it’s important to talk to your doctor about any symptoms or concerns.
In general, careful monitoring and some lifestyle changes can lower your risk of developing complications from high blood pressure.