When Pregnancy Raises Your Blood Pressure

Hypertension, or high blood pressure, is one of the most frequent complications of pregnancy. That’s why it’s important that your blood pressure is routinely checked at each prenatal visit. If your blood pressure is abnormal, your doctor will do a work-up to determine possible causes and find the right treatment to maintain your and your fetus’s health.

Blood pressure refers to the force of blood pushing against artery walls as it flows through the body. A blood pressure reading appears as two numbers. The first and higher of the two is systolic and refers to the pressure in the arteries when the heart beats and fills them with blood. The second number is diastolic and refers to the pressure in the arteries when the heart rests between beats. A blood pressure of 120/80 means that your systolic pressure is 120 millimeters of mercury (mm Hg), and your diastolic is 80 mm Hg.

When Pregnancy Raises Your Blood Pressure

Most people with hypertension have no symptoms and only learn that their blood pressure is high at a routine doctor’s visit. It’s important to know that you have high blood pressure, however, because the condition puts you at increased risk for complications such as cardiac, renal or optical disease that may not otherwise become apparent for decades.

High blood pressure during pregnancy not only threatens your health and life but also threatens fetal health. Normally, blood pressure decreases from the end of the first trimester through mid-pregnancy and then slowly rises in the last trimester toward normal pre-pregnancy levels.

A diagnosis of high blood pressure isn’t much different during pregnancy than at any other time. You could be diagnosed with hypertension if your blood pressure is at least 140/90 on at two occasions. In addition, if your systolic pressure rises more than 30 points and your diastolic pressure rises more than 15 points over your average pregnancy levels, there’s a possibility you could develop pre-eclampsia, a potentially serious form of high blood pressure that occurs late in pregnancy. At 14 weeks, it’s unlikely that pre-eclampsia is the problem.

The most widely used U.S. classification system for high blood pressure in pregnancy was developed by the National Heart, Lung and Blood Institute of the National Institutes of Health. NHLBI classifies elevated blood pressure during pregnancy into four categories:

Chronic hypertension

  • Pregnancy-induced hypertension (including pre-eclampsia and eclampsia)
  • Pregnancy-aggravated hypertension (superimposed pre-eclampsia)
  • Transient hypertension

Chronic hypertension is diagnosed when you have high blood pressure:

  • before the pregnancy; or
  • if it’s diagnosed before the 20th week of gestation; or
  • if it persists beyond the 42nd day.

In your case, the diagnosis was probably made because you were found to be hypertensive before 20 weeks. One in 40 to 50 women of childbearing age has chronic hypertension, which often runs in families and is more common in certain ethnic groups such as African Americans or Mexican Americans. Another word for this condition is “essential hypertension,” which means there’s no obvious cause.

Pregnant women with chronic hypertension face a greater risk of complications, including superimposed pre-eclampsia, abruptio placentae, intrauterine growth restriction (IUGR), stillbirth, and kidney and heart problems.

Right now, there’s little agreement among high-risk-pregnancy specialists about how to treat chronic hypertension in pregnancy — which medications to use, for example, or whether bed rest helps. Many doctors prescribe antihypertensive drugs during pregnancy when the blood pressure is above 150/100 with the goal of keeping the pressure below 140/90. The most frequently used medication is alpha-methyldopa.

Women with chronic hypertension should be checked throughout pregnancy for possible complications, and the fetus should be monitored for IUGR and placental insufficiency. Some doctors suggest that you monitor your blood pressure at home and call the office or the hospital if it reaches critical levels. You’d also be advised to contact your doctor if you have headaches, abdominal pain or vaginal bleeding, or if you perceive decreased fetal movements.

But with proper diagnosis and treatment, most pregnant women with chronic hypertension will deliver healthy babies.

The information contained in or made available through This Site cannot replace or substitute for the services of trained professionals in the medical field. We do not recommend any treatment, drug, food or supplement. You should regularly consult a doctor in all matters relating to physical or mental health, particularly concerning any symptoms that may require diagnosis or medical attention.

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