What is chronic hypertension?
If you had high blood pressure (also called hypertension) before you got pregnant or you’re diagnosed with it before you reach 20 weeks, you have chronic hypertension. Up to 5 percent of pregnant women have chronic hypertension.
A blood pressure measurement tells how hard your blood is pushing against the walls of your arteries. The measurement has two numbers: The top (systolic) number is the pressure when the heart pumps blood, and the bottom (diastolic) number is when the heart relaxes and fills with blood. High blood pressure during pregnancy is defined as a reading of 140/90 or higher, even if just one of the numbers is elevated. Severe chronic hypertension is 180/110 or higher.
Because your blood pressure may vary, your healthcare practitioner may take readings at several different times and use the average reading.
Chronic hypertension isn’t the only condition that involves high blood pressure during pregnancy. If you develop high blood pressure after 20 weeks of pregnancy, you’ll be diagnosed with gestational hypertension. If your blood pressure doesn’t return to normal within 12 weeks after giving birth, you probably had chronic hypertension the whole time.
And if you develop hypertension after 20 weeks of pregnancy and have protein in your urine, you have a condition called preeclampsia.
How does having chronic hypertension affect my pregnancy?
Having chronic hypertension significantly increases your risk of developing preeclampsia. Preeclampsia that develops when you already have chronic hypertension is called “superimposed preeclampsia.” Up to 1 in 4 women with chronic hypertension and as many as half of women with severe chronic hypertension will develop superimposed preeclampsia during pregnancy.
High blood pressure during pregnancy can also cause less blood to flow through the placenta, delivering less oxygen and fewer nutrients to your growing baby. Chronic hypertension increases your risk for a number of pregnancy complications, including intrauterine growth restriction, preterm birth, placental abruption, and stillbirth.
If your chronic hypertension is mild, your risk for these complications during pregnancy is not much higher than it would be if you had normal blood pressure – that is, as long as you have no other existing medical problems, your hypertension doesn’t get worse during pregnancy, and you don’t develop superimposed preeclampsia.
The more severe your hypertension, however, the higher your risk for these problems, and developing superimposed preeclampsia increases your risk even more. Your risk is also higher if you’ve had hypertension for a long time and it’s done some damage to your cardiovascular system, kidneys, or other organs, or if your hypertension is a result of an underlying medical condition such as diabetes, kidney disease, or lupus.
How is chronic hypertension managed during pregnancy?
Ideally, if you were receiving care for hypertension before you got pregnant, you discussed your plans to conceive with the healthcare provider who manages your hypertension and let your pregnancy provider know about your hypertension at a preconception visit.
Among other things, she might have changed your high blood pressure medication, because some antihypertensive drugs, such as ACE inhibitors, may raise the risk of birth defects when taken during pregnancy. Your pregnancy provider may also have referred you to a perinatologist (a doctor who specializes in high-risk pregnancies).
If that didn’t happen before you got pregnant, call your provider right away and be sure to discuss any medications you’re on. (If you don’t have a pregnancy provider yet, call the provider who’s been managing your hypertension.) Again, depending on your condition, you may be referred to a perinatologist.
Tests and medication
If blood and urine tests relating to your hypertension haven’t been done recently, your caregiver will probably order a complete set now. And depending on your condition and what’s been done in the past, she may order an EKG, an eye exam, a 24-hour urine collection, and possibly other tests. If this is the first time you’ve been diagnosed with hypertension, then you’ll have a complete work-up, including tests to rule out other conditions that may be causing your high blood pressure.
If you have severe hypertension, you’ll need to continue taking blood pressure medication during your pregnancy. Your doctor may need to switch your usual medication to one that’s safer for your baby, though, especially if you were on an ACE inhibitor-type medication.
She may decide to hospitalize you for a few days so you can be monitored closely until your medication is adjusted and your blood pressure is under control. It’s critically important to keep taking your medication, because severe uncontrolled hypertension can be life-threatening.
If you have mild chronic hypertension (without other complications, such as advanced diabetes or kidney disease), your caregiver may advise you to stop taking your blood pressure medication or to reduce your dose. Being off medication temporarily is unlikely to cause problems if your condition is mild.
If you’re not currently taking blood pressure medication, your caregiver probably won’t recommend starting it now. That’s because pregnancy itself tends to lower your blood pressure at the end of the first trimester and keep it down throughout much of the second trimester, although it returns to its normal level at the end of the second trimester. And if your pressure gets too low, it can actually reduce blood flow to the placenta.
Monitoring you and your baby
Whether your hypertension is severe or mild, it’s important to keep all of your prenatal appointments so your caregiver can monitor you and your baby and spot any developing problems, such as rising blood pressure, signs of preeclampsia, or poor fetal growth.
In fact, you’ll have more frequent prenatal visits and lab tests to monitor how you’re doing. In addition to the usual second-trimester ultrasound, you’ll have periodic ultrasounds in your third trimester to monitor your baby’s growth and your amniotic fluid level, as well as regular fetal testing (nonstress tests or biophysical profiles) and possibly Doppler ultrasounds if the baby’s growth is poor (to check blood flow to your baby).
If at any time during pregnancy your blood pressure gets too high, you’ll be hospitalized until it’s under control, and if you develop superimposed preeclampsia, you’ll be hospitalized until you give birth. Depending on your condition and your baby’s health, you may have to deliver early, even if that means your baby is premature.
You’ll need to pay particular attention to your salt intake: Avoid the saltshaker, try to use fresh foods instead of prepared or processed ones, and check labels for sodium content. If you’ve never had nutritional counseling or are unclear about how to keep your salt intake within the limit recommended by your caregiver, ask for a referral to a registered dietitian who can help devise a diet plan that works for you.
Your practitioner may also recommend cutting back on activity and avoiding aerobic exercise. If you smoke or drink alcohol, it’s now even more important to stop, since they can both make your hypertension worse.
What warning signs should prompt a call to my caregiver?
Once your baby starts moving regularly, your caregiver may ask you to do fetal kick counts to keep track of your baby’s movements. (This is a good way for you to monitor your baby’s well-being between prenatal appointments.) Let your practitioner know immediately if you notice that your baby is less active than usual.
Your practitioner may also have you check and keep track of your blood pressure at home. He’ll tell you how often to do this and will want to see the results at your visits. He’ll also give you directions regarding when to call the office or go to the hospital if your numbers are above certain levels.
Also call your caregiver right away if you have:
- Any headache, but especially a severe, persistent, or pounding one
- A pounding sensation in your chest or heart palpitations
- Swelling in your face or puffiness around your eyes, more than slight swelling of your hands, excessive or sudden swelling of your feet or ankles (some swelling of the feet and ankles is normal during pregnancy), or swelling in your calves
- Weight gain of more than 4 pounds in a week
- Vision changes, including double vision, blurriness, seeing spots or flashing lights, light sensitivity, or temporary loss of vision
- Intense pain or tenderness in your upper abdomen
- Nausea or vomiting (other than morning sickness in early pregnancy)
What will happen after I give birth?
With chronic hypertension, particularly if it’s severe, you’re at risk for complications as your cardiovascular system adjusts to all the changes in your body after you give birth – so after delivery, you’ll be monitored very closely for at least 48 hours.
Also, since preeclampsia can develop after delivery, let your practitioner know immediately if you develop any symptoms of the disorder, even after you’ve been allowed to go home. You’ll start taking blood pressure medication again or have your dosage adjusted as necessary. Let your practitioner know if you plan to breastfeed, because that will affect the choice of blood pressure medication for you.
In addition to taking whatever medication is prescribed and seeing your primary care provider regularly, you’ll need to take good care of yourself to reduce your risk of long-term complications from hypertension, such as heart or kidney disease and stroke. Try to maintain a healthy lifestyle, paying particular attention to your diet and weight, avoiding tobacco, and limiting how much alcohol you drink.
When your postpartum recovery is complete and your practitioner gives you the go-ahead to begin exercising, ask your doctor what kind of exercise routine is best for your individual situation, and stick to it.