Low blood pressure in pregnancy is a very common finding, especially in early pregnancy. It occurs due to hormonal changes that cause the blood vessels to relax, which leads to a drop in blood pressure.
Although it is not as serious as having high blood pressure during pregnancy, a sharp drop in pressure can cause great discomfort and lead to symptoms such as fainting and falls, which can put the baby and the pregnant woman at risk.
To try to keep blood pressure within normal limits, you should avoid sudden changes in position, avoid consuming alcohol, soft drinks and coffee, avoid very hot environments, and eat at regular intervals.
The main symptoms of low blood pressure in pregnancy are:
- Blurred, double or darkened vision;
- Feeling faint
In more serious cases, you may feel you are losing consciousness. It is important to consult your obstetrician if these symptoms occur frequently.
What to do if you feel faint
In the event of low blood pressure during pregnancy, you should:
- Stop what you are doing
- Sit down, take a deep breath and lean forward, bringing your head towards your knees for a few minutes
- Drink 2 glasses of water
- Lie down in a comfortable position with your legs elevated to help normalize blood flow. If you are in your third trimester of pregnancy, she should lie on her left side
If the symptoms of low blood pressure persist for more than 15 minutes or appear very frequently, it is recommended that you go to hospital or contact your obstetrician.
Why pressure drops during pregnancy
During the first and second trimesters of pregnancy, there is an increase in blood flow, which is necessary to supply blood to the mother, the placenta and the small embryo. At this stage, the woman's body is adapting and creating the necessary conditions for the optimal development of the fetus, therefore blood must circulate faster to meet the body's needs.
In order to circulate faster, the hormones produced during pregnancy cause the blood vessels to relax much more, making the blood reach the placenta faster. This can lower overall blood pressure.
Another cause of low blood pressure is the pressure exerted by the uterus on the aorta and abdominal vena cava. This occurs mainly in the third trimester of pregnancy, when the weight of the uterus is greater, and is known as supine hypotension syndrome.
It is also possible for pregnant women to suffer from orthostatic hypotension, in which dizziness and lightheadedness occur when getting up from a sitting or lying position, or when making any sudden movements. You should ideally get up slowly by sitting for a few minutes and only then get up, preferably with help or some support.
The main risk of low blood pressure during pregnancy is fainting, which can result in a fall and cause trauma to the pregnant woman. Normally, this trauma is mild and doesn't cause more than a minor scare, but if the fainting happens in a place where the fall could be more serious, such as on a staircase, for example, it could put the lives of the pregnant woman and her baby at risk.
Low blood pressure during pregnancy stops being frequent when blood volume increases and the pregnant woman's body begins to adapt by producing more blood. It is only at this stage that the pressure tends to return to normal, so care and attention are needed, especially when going out alone.
How to prevent
To try to keep blood pressure within normal levels and to avoid a sharp drop in pressure, some measures can be taken, such as:
- Always have something salty in your purse, such as saltine crackers or dried fruit, so you don't go too long without eating;
- Drink about 2 liters of water throughout the day and in small quantities, in order to avoid dehydration and a drop in pressure;
- Wear light, comfortable clothing suitable for pregnancy;
- Avoid staying for long periods in very hot and humid environments, as well as avoiding very hot baths;
- Avoid drinking alcohol and soft drinks to reduce the chances of dehydration;
- Practicing light to moderate physical exercise regularly, as it has beneficial effects on blood circulation and blood pressure;
- Avoid sudden changes in position, such as standing up too quickly;
In the case of medication, check with your obstetrician whether it has any side effects on blood pressure.
If low blood pressure is frequent, the pregnant woman should see a doctor for a clinical assessment, because although it is not common, low blood pressure can be a sign of a disease that needs to be investigated and treated before it puts the pregnancy at risk.