What to know about high blood pressure during pregnancy
High blood pressure is affecting more and more pregnant women. According to the Centers for Disease Control and Prevention (CDC), the number of pregnant women who developed high blood pressure in the United States almost doubled between 1993 and 2014.
High blood pressure affects an estimated 6–8 percent of pregnancies in women aged 20–44 in the U.S.
If left untreated, high blood pressure can lead to serious health complications for the mother, her infant, or both. In most cases, however, hypertension is preventable and treatable.
In this article, we will discuss the different types of high blood pressure that a woman can develop during pregnancy, the risk factors and complications of high blood pressure, and how to prevent and treat high blood pressure during pregnancy.
Types of hypertension in pregnancy
A woman may experience chronic hypertension, gestational hypertension, or preeclampsia during pregnancy.
According to the CDC, blood pressure measurements that are greater than or equal to 140/90 millimeters of mercury indicate high blood pressure.
Women can experience one of three types of high blood pressure during pregnancy: chronic hypertension, gestational hypertension, or preeclampsia.
A person may have chronic hypertension before pregnancy, whereas gestational hypertension only occurs during pregnancy.
However, gestational hypertension may sometimes persist after the pregnancy to become chronic hypertension.
Women who have chronic hypertension either had high blood pressure before becoming pregnant or developed it within the first half, or 20 weeks, of their pregnancy.
It is possible for a woman to develop a subtype called chronic hypertension with superimposed preeclampsia.
Women with this condition have high blood pressure and can possibly develop an abnormal amount of protein in their urine, or proteinuria. The presence of protein in the urine can indicate problems with the kidneys. Women may also have changes in liver function.
Gestational hypertension only occurs during pregnancy and without the presence of protein in the urine or changes in liver function. Women usually develop this condition in the second half, or after the first 20 weeks, of their pregnancy.
This form of high blood pressure is typically temporary and tends to go away after childbirth. However, it can increase a woman's risk of developing high blood pressure later in life.
In some cases, the blood pressure will remain elevated after the pregnancy, resulting in chronic hypertension.
Preeclampsia is a high blood pressure condition that women can develop during pregnancy or after giving birth. It is a serious condition that can have severe consequences. It usually occurs in the third trimester. It rarely occurs after delivery, but it is possible.
Doctors often diagnose preeclampsia after taking blood pressure measurements and testing blood and urine samples. Women who develop a mild form of preeclampsia may not experience any symptoms.
If symptoms of preeclampsia do develop, they can include:
- high blood pressure
- excessive swelling of the face and hands
- weight gain due to fluid retention
- shortness of breath
- abdominal pain
- blurred vision
- sensitivity to light
Preeclampsia with seizures, or eclampsia, is a different condition. It can be fatal.
Complications of hypertension for the mother
If hypertension is severe or uncontrolled, it can cause complications for the mother and baby.
High blood pressure during pregnancy puts women at an increased risk of more serious health conditions later in life. One 2013 study revealed that gestational hypertension was associated with a higher risk of ischemic heart disease, myocardial infarction (heart attack), heart failure, and ischemic stroke.
One complication of hypertension is HELLP syndrome. This is a rare life-threatening liver and blood disorder. Doctors consider it to be a severe variant of preeclampsia. HELLP stands for:
- Hemolysis, or the breaking down of red blood cells
- Elevated Liver enzymes, which is a sign of liver damage
- Low Platelet count; platelets are a material that forms blood clots
Other complications associated with high blood pressure during pregnancy include:
- placental abruption, a serious medical condition in which the placenta separates from the wall of the uterus too early
- preterm delivery, or giving birth before the due date, which healthcare providers may advise if the placenta is not providing a enough nutrients and oxygen to the baby or if the mother's life is in danger
Risks of hypertension for the baby
High blood pressure can increase the risk of poor birth outcomes, such as preterm delivery, smaller-than-average size, and infant death.
High blood pressure affects the mother's blood vessels. This can decrease the flow of nutrients through the placenta to the baby, resulting in a low birth weight.
Hypertension-related preterm delivery can result in health complications for the baby. These may include difficulty breathing if the lungs are not fully developed, for example.
Signs and symptoms
A pregnant woman should attend regular prenatal checkups.
The American Heart Association (AHA) call high blood pressure the "silent killer" because most people who have it do not develop symptoms. This means that a person may have high blood pressure without knowing it.
Monitoring blood pressure is an essential part of prenatal care. It is important to remember that women can develop high blood pressure before, during, and after their pregnancy.
It is important that women attend regular prenatal checkups to ensure that their blood pressure and other vital signs are within normal ranges and receive treatment if not.
Also, blood pressure fluctuates in response to small changes in a person's life, such as stress, diet, exercise, and the quality of their sleep. This is why it is so important that people check their blood pressure regularly.
Risk factors for hypertension
Risk factors for gestational hypertension and preeclampsia include:
- a history of preeclampsia
- preexisting hypertension
- pregestational diabetes
- having twins or triplets
- preexisting kidney disease
- some autoimmune diseases
The following are risk factors for a person to develop hypertension:
- having a family history of high blood pressure
- being overweight
- having high cholesterol
- smoking cigarettes
- drinking alcohol
- not exercising often
- becoming pregnant at an older age
- having had high blood pressure during a previous pregnancy
Women with chronic hypertension should continue taking antihypertensive medication during their pregnancy. However, some common antihypertensive medications are not suitable for pregnant women to take, so healthcare providers may recommend a different medication.
If gestational hypertension is severe or a woman develops preeclampsia or eclampsia, a doctor may prescribe medications to lower her blood pressure and help the baby mature if the pregnancy is not full-term. Women may be hospitalized for monitoring.
Healthcare providers may recommend anticonvulsive medications, such as magnesium sulfate, to prevent seizures in people with eclampsia or preeclampsia.
In some cases, a doctor may advise delivery of the baby for treatment. The timing of delivery depends on how severe the mother's condition has become, as well as how far along the pregnancy is.
Women who are pregnant should speak with their healthcare provider about ways to control their blood pressure.
Doctors recommend regular exercise to prevent high blood pressure.
Making simple lifestyle changes, such as getting more exercise and eating a more balanced diet, can help prevent high blood pressure.
It is important to note that some risk factors, such as family history, race, and past pregnancy history, are not within a person's control. For this reason, not all cases of hypertension in pregnancy are preventable.
Some ways to lower the risk of high blood pressure during pregnancy include:
- limiting salt intake
- staying hydrated
- eating a balanced diet that is rich in plant-based foods and low in processed foods
- getting regular exercise
- getting regular prenatal checkups
- avoiding smoking cigarettes and drinking alcohol
Medical professionals tend to recommend that people have regular blood pressure screening, especially when they have risk factors, so that they can begin to treat it early.
High blood pressure, or hypertension, during pregnancy can be life-threatening to a woman in some cases. If left untreated, high blood pressure can cause harm to both the mother and her infant.
It does not always lead to serious health complication, and sometimes, it will go away following childbirth.
Hypertension during pregnancy is typically preventable and treatable.
A doctor must closely monitor hypertension in pregnancy to prevent potentially life-threatening health complications. It is important that women attend regular prenatal evaluations and report any abnormal symptoms to ensure their own health and that of their infant.