One of the most dangerous pregnancy complications that can harm a pregnant woman and her baby is preeclampsia — a condition that typically occurs late in pregnancy and is characterized by high blood pressure and protein in the urine.
But preeclampsia, which affects roughly 5 to 8 percent of all pregnancies, doesn’t stand alone. There are other hypertensive, or high blood pressure, disorders that pregnant women (and those trying to become pregnant) need to know about.
Here’s a lowdown on pre-pregnancy hypertension and gestational hypertension.
About 5 percent of women nationwide have pre-existing high blood pressure when they become pregnant, says David G. Chaffin, M.D. a professor of obstetrics and gynecology at the Marshall University Joan C. Edwards School of Medicine in West Virginia and a specialist in hypertensive disorders with Marshall Obstetrics & Gynecology.
Unfortunately, there aren't signs or symptoms that let you know if you're one of them, which is why the condition often remains unnoticed until pregnancy occurs. But there are risk factors – including family history, advanced age, and obesity – that can put you at increased risk for high blood pressure (defined as 140/90 or higher).
Along with the risks that high blood pressure causes during pregnancy, having high blood pressure before pregnancy puts you at an increased risk of developing preeclampsia once you do become pregnant. In fact, between 10 and 25 percent of women with chronic high blood pressure will develop preeclampsia, according to Kiran Tam Tam, M.D., maternal fetal medicine specialist at Texas Children's Pavilion for Women and assistant professor of obstetrics and gynecology at Baylor College of Medicine in Houston.
If you're planning to become pregnant, get a preconception check-up to make sure that you're as healthy as possible and that your blood pressure is under control.
"The target blood pressure is between 120-139 and 80-89," Dr. Tam Tam says. "If you can achieve that prior to pregnancy, that's beautiful." If you're taking medication for high blood pressure and you're trying to get conceive, talk to your doctor to make sure that your medication is safe to take during pregnancy. And if you become pregnant unexpectedly while taking blood pressure medication, call your doctor right away – you may need to switch to a pregnancy-safe version.
If your health-care provider diagnoses you with pre-pregnancy hypertension, she'll likely prescribe medication – such as Labetalol, Methyldopa, or Nifedipine – to control your high blood pressure. Exercising regularly and making dietary changes (lowering your daily intake of salt, drinking plenty of water, avoiding fried foods and caffeine, etc.) may also help decrease your blood pressure.
Gestational hypertension is high blood pressure (defined as anything at 140/90 or above) that originates late in pregnancy (after 20 weeks gestation). It is similar to preeclampsia, although without other findings, such as protein in the urine or laboratory abnormalities. Why some women develop hypertensive disorder during pregnancy is not entirely known, but it's more likely among women who are pregnant for the first time, are obese, are 35 years or older, have a history of medical conditions, are carrying twins, or are African-American.
"Gestational hypertension can be a precursor to preeclampsia," Dr. Tam Tam says. In fact, as many as 10 to 25 percent of women who develop gestational hypertension will also go on to develop preeclampsia. If you have any blood pressure elevation, it's important that you be monitored and treated throughout your pregnancy. That’s because high blood pressure, with or without preeclampsia, carries serious risks to both a mother and a baby during pregnancy.
"All of the mother's vital organs – the brain, liver, kidney – are at risk," Dr. Tam Tam says. If blood pressure gets to the range of 160/110, it can lead to a stroke or other cerebrovascular accidents in the mother. Chronic high blood pressure also increases your risk of having a small baby and a premature delivery.
The severity of hypertension that arises during pregnancy can vary from woman to woman, so treatment will be decided on an individual basis. Doctors will strictly monitor a woman's blood pressure, as well as the health and well-being of her baby, to ensure that the condition doesn't worsen or endanger her or the baby. Depending on the severity of the high blood pressure, treatment could include bed rest and anti-hypertension medications for the mother or steroids to prepare the baby for delivery.
Although women with chronic high blood pressure or women who develop high blood pressure during their pregnancies are at risk for developing other serious complications, such as preeclampsia, there's not a definite cause-and-effect relationship between the disorders. Not all women who go into pregnancy with high blood pressure or develop it during their pregnancies end up with preeclampsia, and not all women who get preeclampsia have high blood pressure before the disorder develops.
That's why it's important to know that high blood pressure is a serious health complication that can affect otherwise healthy, young, childbearing women and lead to very serious complications down the road for both a mother and Baby. So know your risk factors and include regular blood pressure check-ups in all of your health screenings.