A blood pressure reading of 160/110 or higher during pregnancy is a medical emergency that requires immediate hospital care. A reading of 140/90 or higher, confirmed on two occasions at least four hours apart, signals high blood pressure that needs urgent contact with your provider, though it may not require an ER visit on its own. The critical difference between “call your doctor now” and “go to the emergency room” comes down to both the numbers on the monitor and the symptoms you’re experiencing.
The Two Blood Pressure Thresholds That Matter
Pregnancy-related high blood pressure is classified at two levels, and each calls for a different response.
The first threshold is 140/90. Either number reaching that level (systolic of 140 or diastolic of 90) qualifies as high blood pressure in pregnancy. If you get this reading, take it again after at least four hours. If it’s still elevated, contact your OB or midwife. They’ll likely want to see you that day or the next morning, depending on how far along you are and whether you have other symptoms.
The second threshold is 160/110. This is classified as severe hypertension and is treated as a medical emergency. If your blood pressure hits 160 systolic or 110 diastolic on two readings, you should go to the hospital or call 911. At this level, the risk of stroke, organ damage, seizures, and placental problems rises sharply. Don’t wait for a callback from your provider’s office.
Symptoms That Mean Go Now, Regardless of Numbers
Sometimes blood pressure doesn’t tell the whole story. Preeclampsia, the most dangerous blood pressure condition in pregnancy, can cause organ damage even before readings reach the severe range. The following symptoms warrant an emergency room visit whether or not you have a blood pressure cuff at home:
- Severe headache that doesn’t go away with rest or typical pain relief
- Vision changes including blurred vision, seeing spots or flashing lights, light sensitivity, or temporary vision loss
- Pain in the upper right abdomen, just below the ribs, which can signal liver involvement
- Severe shortness of breath, which may mean fluid is building up in the lungs
- Sudden swelling of the face and hands, especially if it appears rapidly rather than building gradually
- Nausea or vomiting that starts in the second half of pregnancy after morning sickness has passed
- Mental confusion or altered behavior, which can be a warning sign of impending seizures
These symptoms can appear before blood pressure spikes high enough to trigger alarm on a home monitor. In one documented case of eclampsia, a woman had seizures at a blood pressure of only 140/90, which would not have been classified as severe by numbers alone. Preeclampsia can also develop with no noticeable symptoms at all, which is why routine prenatal visits that check blood pressure and urine are so important.
When This Can Happen
Pregnancy-related high blood pressure develops after 20 weeks of gestation. Any hypertension detected before that point is considered a pre-existing condition. The risk doesn’t end at delivery. Blood pressure typically peaks between days 3 and 7 after birth, making the first week postpartum a particularly high-risk window. Most cases of postpartum preeclampsia show up within 48 hours of delivery, but the condition can develop up to six weeks later.
Most obstetricians treat severe blood pressure readings as a medical emergency for up to six weeks after delivery. If you’ve gone home after having your baby and develop a severe headache, vision problems, or high blood pressure readings, treat it with the same urgency you would during pregnancy. Blood pressure that was elevated during pregnancy should fully resolve by 12 weeks postpartum.
What Happens at the Hospital
When you arrive with high blood pressure, the team will move quickly to assess both you and your baby. Expect repeated blood pressure checks, blood draws to evaluate your liver function, kidney function, and platelet count, and a urine test to check for protein, which is one of the hallmarks of preeclampsia. A protein level above a specific threshold in your urine, combined with high blood pressure, confirms the diagnosis.
Your baby will be monitored with a cardiotocograph, a device strapped to your belly that tracks the baby’s heart rate and any contractions. If preeclampsia or severe hypertension is confirmed, they may also perform an ultrasound to check your baby’s growth, amniotic fluid levels, and blood flow through the umbilical cord.
If blood pressure is in the severe range, you’ll receive medication to bring it down. If there are signs of impending seizures, a medication called magnesium sulfate is given intravenously to prevent them. Depending on how far along you are and how severe the condition is, the medical team will decide between close monitoring with continued pregnancy or delivery. Delivery is the only cure for preeclampsia, so the decision often comes down to balancing your baby’s maturity against the risks of continuing the pregnancy.
A Serious Complication to Know About
HELLP syndrome is a severe form of preeclampsia that affects the blood and liver. The name stands for hemolysis (destruction of red blood cells), elevated liver enzymes, and low platelet count. It can develop rapidly and sometimes appears without the classic warning signs of preeclampsia. Symptoms often overlap: upper right abdominal pain, nausea, headache, and general malaise that can be mistaken for a stomach bug. HELLP syndrome is diagnosed through blood tests and requires immediate hospital treatment, often including urgent delivery.
Placental Abruption Warning Signs
High blood pressure increases the risk of placental abruption, where the placenta separates from the uterine wall before delivery. This cuts off oxygen and nutrients to the baby and can cause dangerous bleeding for the mother. Symptoms include sudden abdominal pain, back pain, uterine tenderness or rigidity, and contractions that come one right after another. Vaginal bleeding may or may not be present, because blood can become trapped inside the uterus. If you experience sudden, severe abdominal or back pain alongside high blood pressure, get to the hospital immediately.
How to Monitor at Home
If you’ve been diagnosed with gestational hypertension or are at risk for preeclampsia, a home blood pressure monitor is one of the most useful tools you can have. Use a device that’s been validated for use in pregnancy, as not all consumer monitors are accurate for pregnant women. Your provider can recommend specific models.
When taking a reading, sit quietly for five minutes first. Use the correct cuff size for your arm. Don’t talk during the measurement, and avoid caffeine beforehand. Take readings at consistent times each day. Write down every result so you can share them at appointments or reference them if you need to call your provider.
Your care team should give you a specific blood pressure number at which to call them. Common thresholds used in clinical practice range from 140/90 to 155/100, depending on your individual risk profile. If you haven’t been given a clear threshold, ask for one at your next visit. Knowing your personal “call now” number removes the guesswork during a stressful moment.