High blood pressure and pregnancy

KEY POINTS

  • High blood pressure can cause problems for you and your baby during pregnancy, including preeclampsia and premature birth. 

  • High blood pressure usually doesn’t cause signs or symptoms. Go to all of your prenatal care visits so your provider can check your blood pressure. 

  • If you need medicine to keep your blood pressure under control, take it every day. 

  • If you’re at high risk for preeclampsia, your provider may want you to take low-dose aspirin to help prevent it. 

What is high blood pressure?

Blood pressure is the force of blood that pushes against the walls of your arteries. High blood pressure (also called hypertension) is when the force of blood against the walls of the blood vessels is too high. It can stress your heart and cause problems during pregnancy.  If not treated, it can cause problems during pregnancy, like premature birth and preeclampsia.
Some women have high blood pressure before they get pregnant. Others have high blood pressure for the first time during pregnancy. About 8 in 100 women (8 percent) have some kind of high blood pressure during pregnancy. If you have high blood pressure, talk to your health care provider. Managing your blood pressure can help you have a healthy pregnancy and baby.

How do you know if you have high blood pressure?

Your blood pressure reading is given as two numbers:

  1. Systolic blood pressure. This is the upper (first) number in your reading. It’s the pressure when you heart contracts (gets tight). Your blood pressure is highest when your heart beats and pumps blood.
  2. Diastolic blood pressure. This is the lower (second) number in your reading. It’s the pressure when your heart relaxes. Your blood pressure falls because your heart is at rest between beats.

Your blood pressure reading fits into one of five categories:

  1. Normal. Your blood pressure is less than 120/80.
  2. Elevated. Your systolic blood pressure is between 120-129 and your diastolic pressure is less than 80.
  3. Stage 1 high blood pressure. Your systolic pressure is between 130-139 or your diastolic pressure is between 80-89.
  4. Stage 2 high blood pressure. Your systolic pressure is at least 140 or your diastolic is at least 90.
  5. Hypertensive crisis. Your systolic pressure is higher than 180 and/or your diastolic pressure is higher than 120.

At each prenatal care checkup, your provider checks your blood pressure. Your blood pressure can go up or down during the day.

What can you do to manage high blood pressure during pregnancy?

  • Go to all your prenatal care checkups, even if you’re feeling fine. Your provider checks your blood pressure at each prenatal visit.
  • If you take medicine for blood pressure, take it exactly as your provider tells you to.
  • Eat healthy foods. Don’t eat foods that are high in salt, like soup and canned foods.
  • Do something active every day. Try to get 30 minutes of activity each day.
  • Don’t smoke, drink alcohol or use harmful drugs.

What pregnancy complications can high blood pressure cause?

Problems for moms include:

  • Preeclampsia. This is when a pregnant woman has high blood pressure and signs that some of her organs, like her kidneys and liver, may not be working properly. Signs and symptoms of preeclampsia include having protein in the urine, changes in vision and severe headaches. Without treatment, preeclampsia can cause serious health problems, including kidney, liver and brain damage. In rare cases, it can lead to life-threatening conditions called eclampsia and HELLP syndrome. Eclampsia causes seizures and can lead to coma. HELLP syndrome is when you have serious blood and liver problems. HELLP stands for hemolysis (H), elevated liver enzymes (EL), low platelet count (LP).
  • Gestational diabetes   
  • Heart attack (also called myocardial infarction)
  • Kidney failure
  • Placental abruption. This is a serious condition in which the placenta separates from the wall of the uterus before birth. If this happens, your baby may not get enough oxygen and nutrients in the womb. You also may have serious bleeding from the vagina.
  • Postpartum hemorrhage (also called PPH). This is when a woman has heavy bleeding after giving birth. It’s a serious but rare condition.
  • Pulmonary edema. This is when fluid fills the lungs and leads to shortness of breath.
  • Stroke. This is when blood flow to your brain stops. Stroke can happen if a blood clot blocks a vessel that brings blood to the brain or when a blood vessel in the brain bursts open.
  • Pregnancy related death

If you have high blood pressure during pregnancy, you’re also more likely to have a cesarean birth (also called c-section).
Problems for babies include:

  • Premature birth  
  • Fetal growth restriction. High blood pressure can narrow blood vessels in the umbilical cord. If you have high blood pressure, your baby may not get enough oxygen and nutrients from the umbilical cord, causing him to grow slowly.
  • Low birthweight.
  • Fetal death.
  • Neonatal death.

What kinds of high blood pressure can affect pregnancy?

Two kinds of high blood pressure that can happen during pregnancy:

  1. Chronic hypertension. This is high blood pressure that you have before you get pregnant or before 20 weeks of pregnancy. It doesn’t go away once you give birth. About 1 in 4 women with chronic hypertension (25 percent) has preeclampsia during pregnancy. If you’re at high risk for preeclampsia, your provider may treat you with low-dose aspirin to prevent it. If you were taking medicine for chronic hypertension before pregnancy, your provider makes sure it’s safe to take during pregnancy. If it’s not, he switches you to a safer medicine. Don’t stop taking any medicine before you talk to your health care provider. Even if you didn’t take blood pressure medicine in the past, you may need to start taking it during pregnancy.
  2. Gestational hypertension. This is high blood pressure that only pregnant women can get. It starts after 20 weeks of pregnancy and usually goes away after you give birth. It usually causes a small rise in blood pressure, but some women develop severe hypertension and may be at risk for more serious complications later in pregnancy, like preeclampsia.