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All sorts of things happen to your body during pregnancy. Your blood pressure is also subject to change. Usually it remains fairly constant during the first trimester to the level it was before the pregnancy, but it often drops in the second trimester and then returns to the old level. However, many pregnant women also experience high blood pressure. Why this is and whether it can do any harm, you can read all about it in this blog. 

What is blood pressure?

When your blood is pumped around, there is pressure on the arteries. This pressure is called blood pressure. When the heart squeezes, the pressure is at its highest, when it relaxes, the pressure is at its lowest. These different 'pressures' are called upper and lower pressure respectively. The average blood pressure is 120/80 (upper/ lower pressure), but it can also be higher or lower. It is good to know what your blood pressure is before you become pregnant so that you can compare it properly with your blood pressure during the pregnancy. Perhaps your normal blood pressure is already on the low side and therefore there is nothing wrong with it when a blood pressure of, for example, 100/70 is measured (The Midwife). 

High blood pressure

High blood pressure (also known as hypertension) is the most common pregnancy disorder. About one in ten pregnant women will be confronted with it. This percentage is slightly lower in women who have been pregnant before. As long as the negative pressure stays below 90, there is no problem and no increased risk of complications. Should it exceed 90, the midwife will consult with the gynaecologist (UMC Utrecht). If the blood pressure is too high, the baby receives less nutrients and oxygen through the placenta. In most cases, the gynecologist prescribes medication to lower the blood pressure and sometimes the birth is induced earlier (The Midwife). 

It used to be said that a limited salt intake would lower blood pressure, but unfortunately this has little or no effect on high blood pressure during pregnancy. Many doctors advise you to take rest. Perhaps that means taking a temporary break from work or getting a little more help at home. 

Low blood pressure

We speak of low blood pressure (or hypotension) when it is lower than 100/60. Many women experience low blood pressure in the second trimester. This has various causes: 

  • There is a lot of extra blood present in the body that is meant for the placenta to grow your baby properly.
  • The blood vessels become weaker under the influence of pregnancy hormones. They contract less forcefully.
  • Some women suddenly experience low blood pressure when lying on their back. The uterus then compresses the vena cava, making it harder for blood to travel from the body to the heart. 

Low blood pressure is not dangerous, but it is annoying. Many women experience dizziness, palpitations or tinnitus. If you get dizzy when standing up, try crossing your legs and tensing them. That way the blood is less likely to run downhill. Drink enough, move around enough and try sleeping on your left side. This prevents the hollow vein from being blocked ( 

So, Mom...

If your blood pressure is too low, it will not cause any harm. If it is too high, it needs to be closely monitored. You are in good hands with your midwife and possibly your gynaecologist. Stay calm, listen to your body and take good care of yourself. Then you and the little one will be just fine!