When you’re pregnant your blood pressure will be checked on your prenatal visits, but it’s important for you to monitor your blood pressure at home. In fact, it’s a good idea to know what your blood pressure is before you get pregnant, so you have a baseline to refer to as you track your blood pressure in pregnancy.
I strongly recommend you purchase a wrist blood pressure cuff and keep it handy during your pregnancy. Take your blood pressure about the same time at least once a day. These wrist cuffs may not be as accurate as a cuff that wraps around your upper arm, but they are accurate enough to watch the increases and decreases in your blood pressure.
What Do the Numbers in a Blood Pressure Reading Mean?
Blood pressure is the force of your blood pushing against the walls of your arteries. The blood pumped into your arteries moves at a certain rate depending upon whether your heart beating or resting between beats. The beat is always the same length. What changes is the time between beats when your heart muscle is nourished by blood and oxygen. That’s why a rapid heartbeat (tachycardia) is so dangerous
Blood pressure is recorded in a set of two numbers separated by a slash mark, such as 90/110. The first number, the systolic pressure, indicates the pressure in your arteries as your heart beats. The second number, the diastolic pressure, indicates the pressure in your arteries between each heartbeat during the time y our heart muscle relaxes.
It is extremely important to understand that normal blood pressures vary from person to person. For one person, it might be 90/50. For another 130/80. If you know your baseline blood pressure, you can compare your baseline blood pressure before you were pregnant with the variations you find during your pregnancy. Whether blood pressure is high, normal, or low is relative to your baseline.
Blood Pressure During Pregnancy
Blood pressure normally goes up and down during the length of your pregnancy. Your blood pressure usually drops in the first trimester, stays low in the second trimester, and then gradually increases in the third trimester.
The American Academy of Obstetricians and Gynecologists recommend that a patient’s blood pressure needs attention once her blood pressure reaches 160/100. In my experience, this is too high. A blood pressure of 140/90 may well indicate developing pre-eclampsia. In fact, an elevated blood pressure is often the only the only sign of the onset of pre-eclampsia
Based upon what I’ve seen in 6,000 pregnancies, blood pressure hardly ever rises precipitously. It almost always rises slowly and predictably. In my experience, it is far better to treat the rising blood pressure in its early stages which may be as simple as cutting back on your work load. If you work 12-hour shifts, cut the shifts back to 5 to 8 hours on fewer days.
For more information about blood pressure and pregnancy, please see my blog post “Blood Pressure, Blood Loss, and Pre-Eclampsia in Pregnancy.” I also have a podcast about blood pressure on YouTube. My e-book Safe Pregnancy Explained has a chapter on managing blood pressure at home during your pregnancy.