As part of routine pregnancy check-ups, your doctor will check your blood pressure, which is the force of blood pushing against the walls of arteries.
It is common for women to have lower blood pressure, or hypotension, through the second and third trimesters of pregnancy.
While normal blood pressure is important to staying healthy, low blood pressure during pregnancy is usually not cause for concern, unless you experience symptoms from it.
Typically, it’s a sign of your body’s changing hormone balance in order to support the fetus.
However, in some cases, it can be a sign of serious medical issues.
In this article, I’ll discuss why pregnancy causes low blood pressure, and what blood pressure reading is considered too low.
I’ll explain the dangers of low blood pressure during pregnancy, and whether low blood pressure affects the baby.
I’ll talk about common causes of low blood pressure besides pregnancy, and diagnosis of blood pressure during pregnancy.
I’ll also discuss treatment of low blood pressure and provide suggestions on how to live with low blood pressure during pregnancy.
Finally, I’ll explore postpartum blood pressure.
Why Pregnancy Commonly Causes Low Blood Pressure
During pregnancy the circulatory system expands rapidly, which, together with hormonal changes, can cause blood pressure to drop.
Through about 12 weeks and well into the third trimester, common to have low blood pressure.
After you give birth, your blood pressure will typically return to pre-pregnancy level.
What Blood Pressure Reading is Considered Too Low?
Blood pressure is measured in millimeters of mercury (mm HG) and recorded with two numbers.
The first is systolic blood pressure, which is the pressure in your arteries while your heart is pumping blood throughout the body.
The second is diastolic blood pressure, which is the pressure in your arteries while your heart is at rest in between heartbeats.
For most adults, normal blood pressure is 120/80 mmHG.
Blood pressure can vary over the course of a few hours depending on what you’re doing and the time of day.
Blood pressure is considered very low when it’s less than 90/60 mm Hg.
Dangers of Low Blood Pressure During Pregnancy
Low blood pressure during pregnancy is often normal.
But if you experience significant symptoms associated with low blood pressure, you should tell your doctor.
In some cases, low blood pressure may be a sign of ectopic pregnancy.
This is especially a concern if your blood pressure drops suddenly, or over a short period of time.
This type of pregnancy occurs when a fertilized egg grows outside the uterus, usually the fallopian tubes.
Since fallopian tubes can’t expand like the uterus to accommodate a fetus, they can rupture as the fertilized egg grows.
A rupture can lead to a high amount of internal bleeding, which can cause lower blood pressure.
Ectopic pregnancy is life-threatening and needs immediate medical attention.
Extreme drops in blood pressure can lead to other serious medical issues that should also be treated right away.
For instance, shock can occur when certain organs don’t get enough oxygen and nutrients after blood pressure drops too low.
Blue and cold or sweaty skin, weak and rapid pulse, or rapid breathing are signs of shock.
Does Low Blood Pressure Affect the Baby
There is extensive research on the dangerous effects that high blood pressure during pregnancy can have on a baby.
However, more research needs to be conducted on the effects low blood pressure can have on a baby during pregnancy.
One study found that low maternal blood pressure during pregnancy does not indicate an increased risk of perinatal death (stillbirths and early early neonatal deaths).
Again, more research is necessary to understand how low blood pressure may affect the baby.
Low blood pressure can cause the following symptoms:
- Blurry vision
- Cold, sweaty, or pale skin
Low blood pressure can lead to severe symptoms. For instance, dizziness, weakness, and lightheadedness increase risk of falling, which can be harmful to you and your baby.
Fainting is another severe symptom that low blood pressure can cause. If you’re experiencing these symptoms, discuss them with your doctor right away.
Common Causes of Low Blood Pressure Besides Pregnancy
Aside from pregnancy, other common causes of low blood pressure include:
- Anti-anxiety medication
- Particular antidepressants
- Heart medications
- Irregular heartbeat
- Heart failure
Diagnosis of Blood Pressure During Pregnancy
Your healthcare provider can diagnose low blood pressure with a blood pressure test.
The process is painless and takes about a minute to complete.
First, your healthcare professional will wrap an inflatable cuff around your bare arm.
If they’re using an automated device, then the cuff will automatically inflate and tighten around your arm. It will also measure pressure as the cuff inflates and deflates.
You can measure your blood pressure at the doctor’s office, pharmacies with blood pressure machines, or at home.
Treatment of Low Blood Pressure During Pregnancy
Low blood pressure during pregnancy is common, and typically does not require treatment unless it is associated with concerning symptoms..
If medication could be the cause of low blood pressure, your doctor may change your dosage or prescribe another medication.
Tips for Living with Low Blood Pressure While Pregnant
While medication generally isn’t prescribed for pregnant people with low blood pressure, there are steps that can help manage or prevent symptoms.
Avoid standing up too quickly
Pregnancy can cause orthostatic hypotension, which is a sudden drop in blood pressure after standing up from a sitting or lying position.
With orthostatic hypotension, standing up too quickly with low blood pressure may cause you to feel faint or dizzy.
This can increase your risk of falling or even fainting.
Don’t stand for too long at one time
Low blood pressure can occur after standing for long periods of time, leading to dizziness and fainting.
If you already have low blood pressure, avoid standing for long periods of time and sit down right away if you begin to feel faint.
Eat small, frequent meals
Low blood pressure can drop excessively after eating and cause dizziness, lightheadedness, and falls.
Frequently eating small meals that are low in carbohydrates may help prevent symptoms.
Avoid very hot showers or baths
Hot showers and baths may cause blood vessels to dilate, which can further lower blood pressure.
Dehydration can reduce blood volume and lead to low blood pressure.
Drinking plenty of water can help prevent dehydration.
Wear loose clothing
Wearing loose clothing may help prevent dizziness.
However, wearing compression socks or stockings may also help improve circulation.
Postpartum Blood Pressure
Healthcare professionals will monitor your blood pressure after you give birth.
Your blood pressure will typically get checked during postnatal check-up as well.
Research shows that blood pressure usually peaks three to six days postpartum.
However, after that, it should return to its pre-pregnancy levels.
If you have more questions about blood pressure or are experiencing symptoms of low blood pressure, K Health can help. Did you know you can get affordable primary care with the K Health app?
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Frequently Asked Questions
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
Low blood pressure in pregnancy. (2007).
Postpartum hypertension. (2017).
Low Blood Pressure - When Blood Pressure Is Too Low. (2016).
Low blood pressure. (2021).
Measuring Blood Pressure. (2021).
Low blood pressure (hypotension). (2020).
Ectopic pregnancy. (2021).