High Blood Pressure in Pregnancy

Our service at the UW Medicine Maternal and Infant Care Clinic will evaluate, monitor and manage your high blood pressure (hypertension) while you are pregnant. We will also work with you to decrease your likelihood of developing preeclampsia (pree-ee-clamp-see-uh – a high blood pressure pregnancy complication) during pregnancy.

We will partner with you to:
  • Improve your blood pressure.
  • Monitor your baby’s well-being.
  • Achieve delivery at or near term.

The Care Team

The care team includes maternal-fetal medicine doctors (also called perinatologists or high-risk obstetricians), registered nurses, and a medical assistant. We will work with you to obtain the best possible outcome for you and your baby.

The care team will teach you and your family about:
  • Normal blood flow changes during pregnancy.
  • Your risk status and what you can do to help manage these risks.
  • How to recognize the signs and symptoms of preeclampsia, its treatment, and how we can work together as a team to manage it.
  • Your care plan and treatment options to maintain a normal blood pressure and to optimize your health and your baby’s health.
  • What you can expect during labor, after delivery, and with breastfeeding.

Your Clinic Visits

You will see a doctor at each visit. Your doctor will go over your prenatal records, medical history, labs, test results, and explain your plan of care. The test results and plan of care will be shared with your prenatal provider through a phone call and with a letter that will be placed in your medical file.

You will be seen several times during your pregnancy. Your medical condition and gestational age (how far along you are in the pregnancy) will determine the date of your next visit. A treatment plan will be tailored just for you.

Your treatment plan may need adjustments as you move through pregnancy. It is important to your health and your baby’s health to come to all of your scheduled visits. 

Cardiac Output Measurement and Your Blood Pressure

Your cardiac output will be measured at every visit to the Hypertension Consult Clinic. A specialized ultrasound machine will measure the amount of blood that is pumped through your body each minute (cardiac output). The test takes about 15 minutes.

Blood pressure is a combination of cardiac output and the amount of constriction or tightness in your blood vessels (peripheral resistance). If either your cardiac output or peripheral resistance is higher than average, it can cause your blood pressure to increase.

It is normal for a woman’s blood flow to change dramatically throughout pregnancy to meet the demands of a growing baby (or babies). Usually these changes start in the first trimester of pregnancy and stabilize after 14 to 16 weeks of pregnancy.

Your cardiac output measurement provides information about your blood flow during your pregnancy. Each measurement will be plotted on a pregnancy blood flow graph and compared with the expected values for that point in pregnancy. The results will give you and your providers more information about your risk for developing preeclampsia later in pregnancy, and how to best treat you. The results will help the doctor decide if medications are needed, and show which one(s) would be most effective for you and your baby.

About Preeclampsia

Preeclampsia is a high blood pressure complication of pregnancy that can happen any time after the 20th week of pregnancy. If untreated, it can affect many systems of the body, including the kidneys, liver, and brain. Delivery of the baby is necessary if preeclampsia has advanced to a stage where it threatens the health of the mother and baby.

This can be a major problem if it occurs when the baby is not mature, or preterm. We use medications and rest to delay its development or slow its progression so that baby can be delivered as close to term as possible. A woman with preeclampsia will likely have increased blood pressure, protein in her urine, and other changes in her blood, measured through specific lab tests. 

Risk Factors

Our goal is to decrease your risk for developing preeclampsia instead. Women who have these conditions are at a higher risk of developing preeclampsia during pregnancy:
  • Chronic hypertension
  • History of preeclampsia (especially preterm)
  • Diabetes
  • Kidney disease
  • Autoimmune disease
  • Borderline blood pressures early in pregnancy (most often greater than 120/80)
  • Blood pressures that don’t decrease in the second trimester
  • First pregnancy

Warning Signs of Preeclampsia

If you have any of these symptoms, you should call your doctor or provider right away:
  • Headaches, which are more frequent or different than are usual for you, especially if they don’t go away with Tylenol or other recommended treatment.
  • Swelling that doesn’t resolve overnight or with rest and goes past your feet and ankles to your hands and face. Rapid weight gain may also happen with swelling.
  • Visual problems such as seeing stars, spots or flashing lights (much like what you may see when you stand up too fast).
  • Epigastric pain (like “heartburn”) felt more on your upper right side and not related to what or when you eat. This type of “heartburn” does not get better with antacids. You may have nausea and/or vomiting.

Things That You Can Do

These are some things that you can do to help lower your risk for preeclampsia or to help us identify problems early so you can avoid a preterm delivery:
  • Come to all of your scheduled prenatal and consult visits.
  • Give a thorough medical history.
  • Eat healthy foods. Avoid salty foods such as chips, canned soups and vegetables, frozen entrees, and soy sauce-based dishes.
  • Take rest breaks. Listen to your body and rest when you’re tired.
  • Take your prescribed medicines regularly.
  • Call your provider to report warning signs and other concerns.

Daytime Rest Breaks

Most women benefit from increased rest late in pregnancy. Begin thinking about ways to lighten your load at home, work, and with childcare. It will be easier to find time for the rest breaks if you have help from the people around you. Make plans in advance with family members, coworkers, and friends to make this possible.

If you are asked to get some additional rest during the day, it is most helpful if you take it in blocks of 2 to 3 hours. You don’t have to sleep during these breaks, but it is important to lie down on your side (not sit) and to not get up and down during the rest break.

These rest breaks help to keep your blood pressure down, increase your blood flow, which can help baby to grow well, and can help reduce your swelling. Listen to your body and don’t push yourself. 


Here is a list of the main blood pressure medicines used to treat high blood pressure in pregnancy. The doctor will recommend the medicine(s) that is best for you.

  • Lowers blood pressure by slowing your heart rate down and decreasing your cardiac output, putting less stress on your blood vessels.
  • May decrease headaches, racing heart, or shortness of breath.
  • Is taken at the same time every day – we sometimes suggest taking it at night since it makes some women feel a little tired.
  • Can slow your baby’s growth if blood flow becomes too low. This is one of the reasons that it’s important to come back for follow-up visits. We can monitor your blood flow/cardiac output and make changes in your treatment to ensure that it does not become too low.
  • Lowers blood pressure by relaxing blood vessels.
  • Is taken 3 times per day. It is important to take this medicine as close to every 8 hours as possible.
  • May cause drowsiness for the first few days.
  • Lowers blood pressure by relaxing blood vessels.
  • Increases blood flow, which is important in maintaining baby’s growth.
  • Is taken 4 times a day either at breakfast, lunch, dinner, and bedtime or every 6 hours.
  • May cause headaches – it is fine to take acetaminophen (Tylenol) for relief, but call your health-care provider if headache pain is not relieved by Tylenol or persists longer than 3 days.
  • Lowers blood pressure by reducing extra body fluids through increased urine output.
  • May be taken once or twice a day. Taking it in the evening may cause you to wake up to urinate during the night.
  • May require potassium supplements (taken with the morning meal). Increased urine output can lower potassium in the blood.