Blood pressure in pregnancy: what the numbers mean

Your blood pressure is written as two numbers. The top one — systolic — is the pressure while your heart is squeezing. The bottom one — diastolic — is the pressure between beats. Both matter, and in pregnancy they behave differently than you might expect.

What usually happens across a pregnancy

For many people, blood pressure dips a little in the second trimester as blood vessels relax, then drifts back up toward the end. That dip is why a reading that looks "low" around 20 weeks is often unremarkable, and why your care team pays closer attention to readings later on.

Why your care team tracks it

High blood pressure in pregnancy can develop quietly. Tracking it gives your team a pattern rather than a snapshot, which is far more useful than a single number taken in a busy clinic room where you may have just climbed a flight of stairs.

Your ranges come from your care team

This app does not set thresholds. Your provider decides what range is right for you and tells the app, and the app tells you when a reading falls outside it. If nobody has given you a range yet, that is a good question for your next visit.

Signs worth a phone call, not a wait

Alongside the numbers, your team wants to hear about a severe headache that will not shift, changes in your vision, pain under your ribs on the right side, sudden swelling in your face or hands, or shortness of breath. Those matter regardless of what the cuff says.

Bringing it to your appointment

Your appointments are short. A trend chart and a one-line note about anything unusual will tell your provider more in ten seconds than a stack of loose paper will in two minutes.