Your prenatal care visits vary from month to month, but three things will remain constant: You'll be weighed, you'll pee in a cup and someone will take your blood pressure. And at some point during your pregnancy, your practitioner may tell you that your blood pressure reading is a bit elevated.

While this might seem scary, try not to panic — it's relatively common among moms-to-be. Gestational hypertension (also called pregnancy-induced hypertension), occurs in 1 out of every 12 to 17 pregnancies among women between the ages of 20 and 44, according to the Centers for Disease Control and Prevention (CDC).[1]

If it's the first time you've had a higher-than-normal reading, in many cases your next blood pressure check will be normal. But even if it isn't, most pregnant women with high blood pressure deliver perfectly healthy babies, though it can require careful monitoring and treatment.

Your best approach to high blood pressure during pregnancy? Strive to schedule and keep every one of your prenatal care appointments so your condition can be tracked and treated. Read on to learn more about what can raise blood pressure in pregnancy and how it's treated.

What is high blood pressure?

High blood pressure — also called hypertension — is when blood exerts too much force against your blood vessels and arteries. Here's what that means in relation to your blood pressure reading: 

The first number your doctor calls out is the "systolic" (or top) number.[2] This is the pressure against your arteries when your heart pushes the blood out. The second number you hear is the "diastolic" (or bottom) reading, which is the pressure when the blood is flowing back to your heart. 

What is considered normal blood pressure during pregnancy?

Normal blood pressure is considered to be 120/80 or less.

What is considered gestational hypertension?

Your blood pressure is considered to be high and you'll likely be diagnosed with gestational hypertension if you have either a systolic number of 140 or a diastolic blood pressure reading of 90.

What is considered low blood pressure during pregnancy?

If you're generally feeling well, nothing is really too low, within reason. But blood pressure that's abnormally low, which is called hypotension, can lead to dizziness and fainting and is represented by a systolic reading lower than 90 or a diastolic number of 60.[3]

What causes gestational hypertension?

It's not clear what's behind every case of gestational hypertension, but there are some risk factors, including a history of long-term high blood pressure or chronic kidney disease. You might also be more at risk if you're Black, you're carrying multiple babies, you have type 1 or 2 diabetes, you're younger than 20 years of age or older than 40, or you're obese.

Another cause of an above-normal blood pressure reading may be a case of "white-coat hypertension" — a pretty common phenomenon (even if you're not expecting), where blood pressure temporarily spikes because you get nervous or worried in medical settings.

Still, if your doctor notices your blood pressure is above 140/90 on two separate visits, whether you're just anxious when that cuff is placed on your arm or you have one of the above-mentioned risk factors, he or she will likely diagnose you with gestational hypertension.

Are there any symptoms of gestational hypertension?

Symptoms can vary from person to person and during each pregnancy, but the main symptom of high blood pressure when you're expecting is a high reading in the second half of gestation, usually around week 20. Yet one of the tricky things about high blood pressure when you're pregnant is that some women feel completely normal and don't show any symptoms at all.

Types of high blood pressure during pregnancy

Blood pressure problems during pregnancy tend to fall into three categories: 

Chronic hypertension

If you have a history of high blood pressure or high readings that show up before the 20-week mark of pregnancy, you likely have chronic hypertension. During the first few months of pregnancy, your blood pressure tends to drop, as blood volume increases and your body starts working long hours to get up to speed, causing occasional bouts of dizziness in early pregnancy.

A blood pressure number that measures high before week 20 means you likely had the condition before pregnancy — and your doctor will consider it a long-term case that needs to be monitored closely, since it puts you at higher risk of preterm delivery and preeclampsia and your baby of low birth weight.

Gestational hypertension

Somewhere near the end of the second trimester or the start of the third, blood pressure rises because your body needs to pump the extra blood it made to nourish your baby. But if your doctor first notices high blood pressure after week 20 and you don't have any other red-flag symptoms, he or she'll likely consider you to be among the roughly 6 percent of women who develop transient (short-term) gestational hypertension.

Gestational hypertension, also called pregnancy-induced hypertension, usually disappears after delivery. But because it can be hard to tell it apart from preeclampsia, if you are diagnosed with hypertension after week 20, your doctor will keep an extra-careful eye out for preeclampsia symptoms including protein in your urine, severe swelling and sudden weight gain. 

Preeclampsia

Preeclampsia is a more serious disorder that puts you at greater risk of premature delivery and fetal growth restriction, and therefore requires very close monitoring and treatment. Preeclampsia is hypertension with additional abnormalities such as protein in the urine, elevated liver enzymes, low platelets or symptoms like headache, severe swelling in the hands and face, or spots in front of the eyes (called scotomata).

Preeclampsia usually develops later in pregnancy, but when it occurs before week 32 of pregnancy, it's considered early-onset preeclampsia. Preeclampsia can also occur in the postpartum period.

Preeclampsia occurs in about 1 in every 25 pregnancies and can lead to seizures in some women, which is a grave condition called eclampsia.

What are possible complications of gestational hypertension?

High blood pressure taxes the blood vessels, which in turn decreases blood flow to the liver, kidneys, brain, heart, lungs, uterus and placenta. When gestational hypertension isn't under control and the placenta isn't getting enough blood, fewer nutrients and oxygen make it to your baby, which can slow fetal growth.

And if gestational hypertension morphs into preeclampsia, premature delivery or placental abruption can occur, which is the too-early separation of the placenta from the uterus. In the worst of cases, stillbirth and eclampsia are possible. Untreated very high blood pressure can also lead to stroke.

Tracking your blood pressure during pregnancy

In addition to keeping all of your prenatal care appointments so your doctor can track your blood pressure readings, you might want to turn to home blood pressure technology, which has become quite good and should be considered fairly reliable.

In fact, for women with high blood pressure concerns, a home monitor is a nice way of taking ownership of one's care and being an active participant. Ask your physician which device he or she'd recommend and then get a quick lesson on how to use it at home.

Managing gestational hypertension

Managing a case of high blood pressure in pregnancy usually involves taking medication such as low-dose aspirin to help prevent preeclampsia. Medications used for treating high blood pressure in pregnancy have been widely studied and are considered safe for your baby.

Your doctor may also recommend that you try to sleep on your left side to keep the pressure off of your inferior vena cava, the vein that carries blood from your lower extremities to your heart.

Close contact with your doctor or midwife is critical for women with high blood pressure problems, since lifestyle changes such as weight loss and reducing salt intake can't help with a high reading the way they can when you're not pregnant. In fact, high blood pressure in pregnancy is rarely lifestyle related and should always involve regular medical check-ins.

Moms-to-be with elevated blood pressure will usually need to deliver early, around 37 or 38 weeks, or when diagnosed if it is past that point. If you are preeclamptic you may need to deliver even earlier as waiting on labor could lead to very serious consequences, including seizures.

High blood pressure during pregnancy isn't that unusual and fortunately it's very treatable. If you attend all of your prenatal care visits and follow your doctor's advice, your case of gestational hypertension should ease up after you deliver your bundle of joy.

For most women, delivery starts the road to recovery, but you may have elevated blood pressure for six to eight weeks after your baby is born. Importantly, preeclampsia can worsen in the weeks immediately after delivery, and if you notice worsening symptoms, get evaluated immediately. 

If you need medication to lower your blood pressure, your practitioner will likely recommend gradually decreasing the dosage over the course of those six to eight weeks.