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High blood pressure is a serious problem that continues to grow in our country. Among women of childbearing age, we see about 20 percent with high blood pressure, whether they know it or not. Many pregnant women are aware of preeclampsia, a type of high blood pressure that endangers both the mother and her baby. But actually, there are four main categories of high blood pressure, also known as hypertension, that are associated with pregnancy:
- Chronic hypertension: high blood pressure diagnosed before the 20th week of pregnancy, which means the mother had high blood pressure before conceiving
- Preeclampsia: high blood pressure that develops after the 20th week of pregnancy or after delivery and is a risk factor for serious complications
- Preeclampsia superimposed on chronic hypertension: preeclampsia that develops in a woman who already had high blood pressure before she became pregnant
- Gestational hypertension: high blood pressure that develops after the 20th week of pregnancy but does not have the same effects on mothers or babies as preeclampsia
High blood pressure during pregnancy is a dangerous risk factor for serious and life-threatening complications, including heart attack, stroke, development of heart disease, and cerebral aneurysm, a weakened, bulging area in the wall of an artery in the brain that may rupture.
Risks of High Blood Pressure During Pregnancy
Mothers and babies tend to have normal, healthy outcomes in cases of gestational hypertension. However, the other types of hypertension can be very dangerous for the expectant mom and the baby without regular monitoring.
Pregnant women with preeclampsia are at increased risk for a number of complications, such as organ or brain damage. Preeclampsia also can develop into eclampsia, which is when elevated blood pressure can result in seizures. Babies whose mothers have preeclampsia might be at risk for:
- Bleeding in the brain
- Premature birth
- Low birth weight
- Retinopathy of prematurity, an eye disorder that can lead to lifelong vision problems or blindness
The first stage of high blood pressure starts at 130 over 80, or 130 millimeters of mercury (mmHg) of systolic pressure and 80 mmHg of diastolic pressure. Most Ob/Gyns use a cutoff of 160 over 100 as an indication that a pregnant woman needs medical treatment for high blood pressure.
In addition to the risks of high blood pressure, we also have to monitor these patients for dangerously low blood pressure. It’s normal for an expectant mom’s blood pressure to drop from the time of conception through the second trimester—about 28 weeks. This is because her blood vessels dilate, or expand, to allow more blood to flow to the baby through the placenta. However, a woman who is on medication for high blood pressure before pregnancy should work with her doctor to adjust her dosage to avoid passing out or not providing enough blood to her baby.
Cardiology Care Can Pinpoint Hypertension Warning Signs
An Ob/Gyn might refer an expectant mom to a cardiologist if she needs monitoring or treatment for high blood pressure beyond what the Ob/Gyn can provide. In addition to regular blood pressure monitoring, expectant mothers receive a number of tests to determine whether they have a form of high blood pressure or to make sure we are keeping it under control. These may include:
- Blood tests to determine how well the liver and kidneys are functioning, as well as levels of blood cells called platelets (which help blood clot). Platelet levels that are too low can be a sign of preeclampsia.
- Fetal ultrasounds to keep track of baby’s growth. If the baby isn’t growing well, it can be a sign of high blood pressure preventing nutrients from flowing through the placenta.
- Urine tests to measure protein levels. Excess protein in the urine can be a sign of kidney problems associated with preeclampsia.
Blood tests, ultrasounds, and urine testing help #cardiologists monitor expectant moms for #preeclampsia and other forms of high #bloodpressure during #pregnancy. via @MedStarWHC
I also educate my patients to watch for swelling of the arms or legs—a common warning sign of preeclampsia. Many pregnant women have some degree of swelling, especially around the ankles, so it can be tough for women to know what’s normal, especially during a first pregnancy. As a general rule, swelling is a concern if they are swollen up to the knee and can press on the swollen area for five seconds and leave a mark, or if the swelling is associated with other symptoms such as breathlessness or difficulty laying flat at night due to breathing. Always err on the side of caution and check with your doctor if you are not sure whether something is normal or serious.
Treatment Options for Managing Blood Pressure During Pregnancy
High blood pressure during pregnancy often can be safely managed with medication, which can be scary for some women. I take patients through the data on medications that have been thoroughly studied and found to be safe for both pregnant women and their babies. Then, we discuss the risks of uncontrolled blood pressure. We work together to come up with the right plan for them, including regular Ob/Gyn and cardiologist visits, to keep both mom and baby safe.
For preeclampsia, the only safe course of action for the mother is delivery of the baby. We work closely with patients’ Ob/Gyns to get their babies to fetal lung maturity, or the point at which the lungs can function well enough for the baby to breathe on their own. That’s usually at about 34 weeks of pregnancy.
Though high blood pressure often doesn’t cause noticeable symptoms, it’s important for pregnant women to control their blood pressure. Hypertension without the right treatment can lead to heartbreaking complications for pregnant women and their unborn babies. If you are not sure about what you are feeling, ask your Ob/Gyn or a cardiologist for help.