What is gestational hypertension?
If you develop high blood pressure after 20 weeks of pregnancy but don’t have protein in your urine or other key symptoms of preeclampsia, you’ll be diagnosed with gestational hypertension, sometimes called pregnancy-induced hypertension (PIH). (Preeclampsia is a serious condition in which women develop high blood pressure after midpregnancy and have protein in their urine, liver or kidney abnormalities, headaches, or vision changes. Women who had high blood pressure before pregnancy – or are diagnosed with it before 20 weeks – have chronic hypertension.)
High blood pressure is generally defined as a reading of 140/90 or higher, even if only one of the numbers is elevated. It doesn’t usually cause any noticeable symptoms unless the blood pressure is really high.
The top number of your blood pressure measurement is your systolic number, which measures the pressure of your blood against the walls of your arteries when your heart pumps blood. The bottom number is your diastolic pressure, a measurement of the pressure when the heart relaxes and fills with blood.
Your practitioner will probably take your blood pressure readings at several different times to determine whether it’s truly elevated.
How can gestational hypertension affect my health and my baby’s?
It depends on how far along you are in pregnancy when you develop gestational hypertension and how high your blood pressure gets. The more severe your hypertension and the earlier in pregnancy it appears, the greater your risk for problems.
The good news is that most women who get gestational hypertension have only a mild form of the condition and don’t develop it until near term (37 weeks or later). If you’re in this category, you still have a somewhat higher risk of being induced or having a c-section, but other than that, you and your baby are likely to do as well as you would if you had normal blood pressure.
However, about 1 in 4 women with gestational hypertension go on to develop preeclampsia during pregnancy or labor, or soon after giving birth. And you have a 50 percent chance of getting preeclampsia if you develop gestational hypertension before 30 weeks.
Having gestational hypertension also puts you at increased risk for a number of other pregnancy complications, including intrauterine growth restriction, preterm birth, placental abruption, and stillbirth. Because of these risks, your caregiver will monitor you and your baby carefully.
What are my chances of getting gestational hypertension?
More than 4 percent of pregnant women in the United States develop gestational hypertension. Your risk is higher if:
- This is your first pregnancy.
- You are obese.
- You are over 40 years of age.
- You are African American.
- You have a personal or family history of gestational hypertension or preeclampsia.
- You have chronic renal failure or diabetes mellitus.
- You are carrying twins or higher multiples.
How is gestational hypertension managed?
Because high blood pressure can affect blood flow through the placenta, if you’re diagnosed with gestational hypertension, your caregiver will order an ultrasound to be sure that your baby has been growing well and to see if you have a normal amount of amniotic fluid. You may also have a biophysical profile (BPP) done at the same time to check on your baby’s well-being. And in certain cases (if your baby’s growth is poor, for example), you’ll have a Doppler ultrasound to check blood flow to your baby.
Your caregiver may also order a set of blood tests and ask you to collect urine for 24 hours to check for protein (this is a more sensitive test than the urine dip done at each prenatal visit). You may also need to check your blood pressure twice a week and get weekly blood tests. These tests will help determine whether you have preeclampsia and allow your caregiver to gauge any later changes in your condition. Finally, you’ll have periodic biophysical profiles or nonstress tests to check on your baby’s health.
Beyond these initial measures, how your caregiver will manage your condition depends on how high your blood pressure is, how your baby’s doing, and how far along you are in your pregnancy. She may ask you to cut back on activity and may refer you to a perinatologist, a doctor who specializes in high-risk pregnancies.
If you haven’t yet reached 37 weeks and your blood pressure is not severely elevated, you may be hospitalized for a few days of monitoring. After that, if you and your baby are doing well, you may be sent home to take it easy or possibly put on some degree of reduced activity.
You’ll need to see your caregiver frequently so she can monitor your blood pressure, check your urine for protein, and watch for changes in your condition. (Your caregiver may also have you check and keep track of your blood pressure at home. She’ll tell you when to call the office or go to the hospital, based on those numbers.)
Your baby will be closely monitored as well with weekly or biweekly BPPs and nonstress tests (NST). You’ll also have ultrasounds every three weeks or so to keep an eye on your baby’s growth.
In addition, your caregiver may ask you to monitor your baby’s movements by doing daily “fetal kick counts.” This is a good way for you to monitor your baby’s well-being between prenatal appointments. Whether you’re doing actual kick counts or not, call your caregiver immediately if you notice that your baby is moving less than before.
You’ll need to be seen immediately if you develop symptoms of preeclampsia (such as swelling, sudden weight gain, persistent or severe headaches, changes in your vision, upper abdominal pain or tenderness, or nausea and vomiting) or signs of placental abruption (such as vaginal spotting or bleeding, or uterine tenderness or pain). If there are any signs of problems with you or your baby, you’ll probably be hospitalized and you may need to deliver your baby.
If your blood pressure is severely elevated (a blood pressure reading of 160/110 or higher), you’ll be given medication to lower your blood pressure and hospitalized until you have your baby. If you’re not yet at 34 weeks, you’ll be given corticosteroids to speed the development of your baby’s lungs and other organs.
If your condition is getting worse, if your baby isn’t thriving inside your womb, or if you’re 37 weeks or more, you’ll be induced or delivered by c-section (depending on the situation), even though your baby is still premature. If you don’t need to deliver right away, you’ll remain in the hospital so both you and your baby can be monitored very closely while your baby has more time to mature.
Will my blood pressure return to normal after delivery?
After you give birth, your blood pressure will be closely monitored and your caregiver will be watching you for signs of worsening hypertension and preeclampsia. (Notify your caregiver right away if you notice any symptoms of preeclampsia, whether you’re still in the hospital or at home.) Most likely, your blood pressure will return to a normal level within a few weeks after you have your baby.
In some women, though, it remains elevated. If your blood pressure is still high three months after you give birth, you’ll be diagnosed with chronic hypertension. That means you probably had chronic hypertension all along and just didn’t know it.
Pregnancy usually causes your blood pressure to go down at the end of the first trimester and through much of the second trimester, so it can temporarily hide chronic hypertension. (It returns to your normal level at the end of the second trimester.) If you didn’t have your blood pressure taken before conception and your first prenatal visit wasn’t until late in the first trimester or so, your hypertension may not have become evident until later in your pregnancy.