What Do You Know about Low Blood Pressure During Pregnancy?


Finding out that your blood pressure is low can be alarming – especially when you’re pregnant. But in many cases, low blood pressure is normal in pregnant women. It may also be a sign of something more serious, especially if other symptoms are present.

Why are pregnantwomen more susceptible to low blood pressure, and is there anything you can do to prevent it?

Understanding Blood Pressure

Low blood pressure during pregnancy
Source: http://www.utswmedicine.org/

Blood pressure is a reading of the pressure in your arteries during the resting and active phases of every heartbeat. There are two numbers included in each reading:

  • Systolic: This is the first, or top, number and relates to the amount of pressure your heart is generating when it’s pumping blood.
  • Diastolic: This is the second, or bottom, number and relates to the amount of pressure in your arteries when your heart is resting (in between each beat).

Medically speaking, a person is considered to have low blood pressure if their reading is lower than 120/80 mmHg.

What Causes Low Blood Pressure during a Pregnancy?

It’s not uncommon for blood pressure to fluctuate throughout a pregnancy. For many women, their blood pressure changes on a daily basis depending on what they’re doing.

Typically, women experience a drop in blood pressure during the first and second trimester. Early on in the pregnancy, your body is producing an immense amount of hormones, mostly progesterone. Progesterone relaxes blood vessel walls, which can cause your blood pressure to plummet. As you inch closer to the third trimester, your blood pressure will slowly start to return to pre-pregnancy levels.

Doctor examining pregnant woman's blood pressure
Source: https://baby-pedia.com

Don’t worry – your doctor or midwife will be keeping a close eye on your blood pressure levels throughout your pregnancy and will let you know if it’s ever in the abnormal range.

Other causes of low blood pressure (which can occur whether you’re pregnant or not) include:

  • Even mild dehydration can cause you to feel tired, dizzy and weak. Severe bouts of morning sickness can make you dehydrated, so keep a close eye on your fluid intake (and loss) throughout your pregnancy.
  • Endocrine issues. A thyroid condition can cause low blood pressure as well as diabetes and hypoglycemia.
  • Blood loss. A major injury or internal bleeding can cause you to lose a lot of blood, which would result in a sharp decline in blood pressure.
  • Septicemia – a severe infection. Septicemia can occur when an infection makes its way into your bloodstream. This can send your body into septic shock, which is the result of a life-threatening decline in blood pressure.

Symptoms of Low Blood Pressure

A slight drop in blood pressure may go unnoticed, but a bigger decline in pressure can cause you to experience:

  • Nausea
  • Dizziness
  • Difficulty concentrating
  • Blurred vision
  • Increased heart rate
  • Clammy, pale and cold skin
  • Excessive thirst
  • Weakness and fatigue

[Read more about Fatigue]

It’s easy to write off these symptoms as just another part of the pregnancy experience. But if they’re making you uncomfortable or you find yourself feeling faint or dizzy on a regular basis, it’s time to see your doctor.

How Low Can You Go?

In a normal pregnancy, systolic pressure may drop 5-10 mmHg, and the diastolic pressure may drop anywhere up to 15mmHg.

The drop in pressure may be enough to generate some side effects (i.e. feeling dizzy or weak), but you should not be experiencing the same symptoms you would get with severe hypertension, or shock.

Why Does Blood Pressure Matter?

Low blood pressure symptoms
Source: http://www.medicinenet.com/

While most women will experience fluctuations in their blood pressure throughout their pregnancy, it’s still important to keep a close eye on it to make sure no underlying medical conditions are developing.

Low blood pressure can be a sign of something more serious, such as:

  • Pre-eclampsia
  • Dehydration
  • Anemia
  • Heart disease
  • Vitamin deficiency (B12 or folic acid)

[Read more about Anemia]

Pre-eclampsia is a serious condition that can be life threatening to you and your baby if it’s left untreated. Your doctor or midwife will perform routine checks of both your blood pressure and your urine to look for signs of this condition.

It’s normal to feel a little dizzy from time to time during your pregnancy, and fluctuations in blood pressure are typically expected. However, if you feel feint, let your doctor or midwife know about your experience, as this is a sign that your blood pressure has dropped dangerously low.

4 Things You Can Do to Keep Your Blood Pressure under Control

A drop in blood pressure may be normal during pregnancy, but that doesn’t mean the symptoms are pleasant. Between morning sickness, aches and fatigue, the last thing you want is to feel dizzy every time you get up out of a chair.

Here are 4 things you can do to help keep your blood pressure under control:

1. Lay On Your Left Side

Pregnant woman lying on her left side
Source: http://philippines.liketimes.me/

There’s a good reason why your doctor told you to lay on your left side: it increases the blood flow to your heart.

Increased blood flow to your heart can help prevent your blood pressure from falling too low, and gives your heart a rest.

2. Wear Compression Stockings

Many doctors recommend compression stockings for patients with low blood pressure – pregnant or not.

Why?  Because they help improve blood circulation, which gives your heart a rest, prevents low blood pressure and ensures that your organs are getting an ample supply of oxygen and nutrients.

3. Avoiding Standing or Sitting for Long Periods of Time

You sit down for an hour, stand up to get a glass of water, and the room starts to spin. This scenario is all too familiar for most pregnant women. Sitting – or standing, for that matter – for long periods of time can make your symptoms worse.

That sudden movement from sitting to standing or vice versa can make you feel dizzy or feint. The best way to prevent this is to avoid standing on your feet or sitting down for too long. Get up and walk around every 20 minutes to keep your blood flowing adequately.

Pregnant woman drinking water in the park
Source: http://babyology.com.au/

4. Eat Small Meals and Stay Hydrated

Eating several small meals throughout the day and keeping yourself well hydrated can prevent your blood pressure from dropping too low. Aim for at least 8-10 glasses of water per day.

Low blood pressure is normal during pregnancy, but if you experience frequent dizzy spells, see your doctor to make sure that an underlying medical condition isn’t to blame.


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