High Blood Pressure During Pregnancy

High blood pressure affects roughly 1 in 7 pregnancies in the US. Most cases are managed well, but some — especially preeclampsia — can become dangerous for mother and baby. Knowing the warning signs and keeping prenatal appointments matters.

Types

Type	Definition
Chronic hypertension	140/90 or higher before pregnancy or before 20 weeks
Gestational hypertension	140/90 or higher for the first time after 20 weeks, without protein in the urine or organ problems
Preeclampsia	High blood pressure after 20 weeks plus protein in the urine or signs of organ involvement (kidneys, liver, platelets, brain, lungs)
Severe range	160 or higher systolic and/or 110 or higher diastolic — needs urgent treatment

Pregnancy uses the 140/90 threshold for diagnosis, not the general US 130/80.

Warning signs of preeclampsia

Contact your care team or go to labor and delivery right away with:

Severe headache that doesn't go away
Vision changes: blurred vision, flashing lights, spots
Pain in the upper right abdomen or under the ribs
Sudden swelling of face or hands, rapid weight gain
Shortness of breath, nausea or vomiting in the second half of pregnancy
A home reading of 160/110 or higher

Preeclampsia can also first appear up to 6 weeks after birth.

Who is at higher risk?

A first pregnancy, preeclampsia in an earlier pregnancy, twins or more, chronic hypertension, diabetes, kidney disease, autoimmune disease, obesity, age over 35 and IVF pregnancy.

Prevention: low-dose aspirin

For women at high risk (and some at moderate risk), US guidelines recommend low-dose aspirin (81 mg daily) starting after 12 weeks of pregnancy. Take it only on your doctor's advice.

Treatment

Medication: labetalol, nifedipine and methyldopa are commonly used in pregnancy. ACE inhibitors, ARBs and some other drugs are not safe in pregnancy — if you take them and are planning pregnancy, talk to your doctor before conceiving.
Monitoring: more frequent visits, home blood pressure checks, urine and blood tests, and ultrasound to check the baby's growth.
Delivery: with preeclampsia, delivery is the definitive treatment; timing depends on severity and weeks of pregnancy.

After birth

Blood pressure often peaks 3–6 days after delivery — keep checking. A history of preeclampsia or gestational hypertension roughly doubles the long-term risk of heart disease, so yearly blood pressure checks and heart-healthy habits are important afterwards.

Measuring at home: How to Check Your Blood Pressure at Home.

This guide is general health education, not personal medical advice. Check with your doctor before you change what you eat, how you exercise or any medication you take. In an emergency, call 911 (US) or your local emergency number.