When you're pregnant, it's common to have high blood pressure. Up to 8% of pregnant women in the U.S. have high blood pressure, usually during their first pregnancies. If you first develop it when you're expecting, it's called gestational hypertension or pregnancy-induced hypertension (PIH).
Most women with gestational hypertension have healthy pregnancies and healthy babies. But high blood pressure during pregnancy can be a sign of other conditions that can be much more harmful. That's one reason why seeing your doctor early and often is so important in keeping you and your baby healthy.
What Is Gestational Hypertension?
Gestational hypertension occurs when your blood pressure rises in the second half of your pregnancy, or earlier if you’re carrying twins. Blood pressure is the force of blood pushing against artery walls through blood vessels. When this force measures more than 140/90 mm Hg and is first spotted at 20 weeks or later in a pregnancy, doctors consider your blood pressure to be high.
The good news is that, if you develop high blood pressure during pregnancy, it should go back to normal about 6 weeks after you give birth.
How Can It Affect My Baby and Me?
High blood pressure can hurt you and your baby. The effects can be mild to very severe. It may cause no problems. Or it may:
- Damage your kidneys and other organs
- Reduce blood flow to the placenta, which means your baby receives less oxygen and fewer nutrients
- Cause your baby to be born too small or too soon. Most babies can catch up on their growth by a few months after birth, but it's healthier if they are born at a normal weight.
- Put you at risk for heart disease or high blood pressure when you become older
Gestational hypertension can be more severe when you're having twins. In severe cases, gestational hypertension leads to preeclampsia, also known as toxemia. It can harm the placenta as well as your brain, liver, and kidneys. With twins, there's a higher chance that the placenta will become unattached.
How to Tell if Gestational Hypertension Is Worse
If you have any of these symptoms of preeclampsia, call your doctor or midwife.
- You feel bloated, your ankles are very swollen, or your face or upper body has swelling when you wake up.
- You have headaches, blurred vision, or you’re sensitive to light.
- You have seizures or convulsions.
- You have a severe pain under your ribs, especially on your right side.
Who Is at Risk for Gestational Hypertension?
You are at greater risk for gestational hypertension if you:
- Are having your first baby
- Were overweight or obese before you became pregnant
- Are age 40 or older
- Are African-American
- Have a history of PIH or preeclampsia
Women pregnant with twins are also at greater risk.
Is There a Test for Gestational Hypertension?
Your doctor will test your blood pressure throughout your pregnancy. It's important to get tested because high blood pressure causes no symptoms unless it is extremely high. If your pressure is higher than normal after 20 weeks, you may have gestational hypertension.
If you get gestational hypertension, your doctor will check you closely for other changes, too. For example, protein in urine can be a sign of damage to the kidneys from preeclampsia.
What's the Treatment?
No treatment is necessary for gestational hypertension, although blood pressure medicine may be used. You may want to talk to your doctor to see if they might recommend a baby aspirin daily starting in the second trimester if you are at high risk as a way to try to prevent developing it.
Can I Lower My Risk?
Although there isn't a way to prevent gestational hypertension, you can do everything in your power to keep yourself and your babies as healthy as possible throughout your pregnancy. (Losing weight and getting in shape before pregnancy will help lessen risks.) Healthy lifestyle choices can help control your blood pressure. And if you work closely with your doctor, you may help catch any problems early. That gives you the best chance for a healthy outcome.
See your doctor. As soon as you think you might be pregnant, see your doctor. And be sure to go to all your scheduled prenatal appointments. Discuss ways you can lessen problems from high blood pressure.
Your doctor will test your blood pressure throughout your pregnancy and may have you monitor it at home.
Take prenatal vitamins. You need more nutrients during pregnancy. According to some studies, two of these nutrients -- folic acid and calcium -- may lower your risk for gestational hypertension. Either way, you should take a prenatal vitamin with these two nutrients, among others, every day. This helps prevent birth defects and helps keep you and your baby healthy.
Eat healthy foods. Make sure the foods you choose are nutritious. Try to put fruits, veggies, whole-grain breads, lean meats, and low-fat dairy products on your plate every day. Ask your doctor whether you should lower your salt intake. And learn what a healthy weight gain is for you during pregnancy.
Get moving. Exercise is one key to a healthy pregnancy. A small study showed that when overweight pregnant women walked on a regular basis, they lowered their blood pressure. Just be sure to talk with your doctor before exercising. There may be limits on what you can do.
Avoid alcohol and cigarettes. Doctors don't know if there is a safe amount for a pregnant woman to drink, so it's best to steer clear. The same goes for smoking. Stopping smoking or drinking alcohol may not be easy. But this is a surefire way to improve the chances for a healthy baby. If you can't stop on your own, get help.