Updated June 10, 2021
There are many reasons why you experience swelling during pregnancy.
Your blood volume increases by 50% and the composition of your blood changes.
This causes blood vessels to leak fluid into the surrounding tissues.
The increase in blood volume and fluid retention (swelling) can account for up to 25% of the weight you gain during pregnancy.
This “water-weight” is lost soon after delivery.
However, the swelling during pregnancy can cause discomfort, especially during the hot summer months.
Swelling during pregnancy can be dramatic, especially during the hot summer.
You can literally retain liters of fluid in your legs and ankles!
It is important to learn how to prevent swelling during pregnancy and why it is significant if swelling occurs in certain areas:
- sacrum (lower back)
As long as the swelling is not a result of a pregnancy-related complication (toxemia, high blood pressure) there are ways you can keep the swelling to a minimum.
How to Prevent Swelling During Pregnancy
Though this may seem counter-intuitive, drinking 8-10 glasses of water per day helps mobilize fluid out of your tissues and back into the bloodstream.
Water also helps flush out toxins in the bloodstream.
The fluid or edema, stored in your tissues outside the bloodstream, is mobilized back into the circulation.
This can literally be liters of fluid stored in your legs.
2. Leg Elevation:
Elevating your legs above the level of your heart facilitates the flow of blood from your lower extremities back to your heart.
This also helps mobilize the fluid in your tissues around your ankles. Once the fluid is back in your bloodstream, your kidneys will remove the fluid
3. Compression stockings:
To prevent the pooling of blood in your legs, the use of compression stockings can be very helpful. Compression stockings are sized and fit by your provider or a medical supply company.
This is to ensure that the proper amount of pressure is applied to the veins.
The amount of pressure must not be too high as it can be constructive and cause worse swelling.
Though you can order compression stockings through our Amazon affiliate links, you should discuss using compression stockings with your prenatal provider.
If you have a problem with varicose veins, management during pregnancy should be addressed by your provider as a preventive measure before swelling starts to occur.
Management of varicose veins associated with swelling is also important to make sure you do not develop phlebitis (vein inflammation) or blood clots.
4. Moderate Exercise:
If cleared by your prenatal care provider, moderate exercise improves circulation and can help prevent blood clots.
If you are required to be on your feet from the moment you leave the house in the morning until you return at night, you can be almost assured you will observe a significant amount of ankle swelling during the day.
Only after you are able to rest and elevate your legs will the swelling start to subside.
Many women find they cannot fit into their shoes during the day due to ankle edema.
5. Reduce Salt Intake:
Table salt is notorious for causing swelling and high blood pressure. Avoid adding extra salt to your food. Most food is prepared with more than enough salt.
Many individuals notice increased swelling after eating a salty meal. Reducing salt intake is a healthy dietary change everyone should consider and not just during pregnancy.
6. Avoid Restrictive Clothing:
Restrictive clothing can act as a tourniquet, which can obstruct the flow of blood back to the heart. This causes the pooling of blood and allows fluid to leak out of blood vessels into the surrounding tissues.
The best visible example of swelling during pregnancy is when you remove your socks and see the impression left behind.
7. Avoid Prolonged Standing:
Especially standing still, as this allows the blood to pool in your lower extremities.
By moving around your muscles contract and this promotes the return of blood to your heart so it can be perfused through your kidneys.
This removes excess fluid and toxins from your system.
*Swelling during pregnancy is common; however, it is important to remember that it can be associated with pregnancy-related complications such as pre-eclampsia (toxemia).
Swelling of the hands and face can be particularly concerning and should be brought to the attention of your prenatal care provider immediately.
What pregnancy complications cause swelling:
It is important to discuss the abnormal causes of swelling during pregnancy as that these conditions must be evaluated and managed promptly by your prenatal care provider:
1. Toxemia (preeclampsia, gestational hypertension)
This is a common problem, particularly among young women having their first baby.
If you have ankle swelling accompanied by swelling in the hands and face this is particularly concerning and a thorough clinical evaluation must be performed to be certain your swelling is not related to toxemia.
2. Phlebitis (vein inflammation) or blood clots:
Though rare, these medical complications can also cause swelling in the ankles and legs.
This form of swelling is associated with other symptoms because it is an inflammatory process.
In addition to ankle swelling, you may notice redness, tenderness, or pain in the calves.
If you must be evaluated immediately to be sure this problem is not the result of a vascular problem.
The evaluation will include a physical exam, ultrasound, and additional studies as deemed necessary.
These vascular conditions must be diagnosed promptly and require treatment.
3. Medical problems unrelated to pregnancy:
Maternal medical problems …. kidney disease, etc. can also cause swelling.
A thorough medical history and physical examination at your first prenatal visit are required to screen for these underlying medical problems.
*Assuming the above conditions (which are not all-inclusive) have been excluded by your prenatal care provider, the cause of your swelling is likely the result of “normal” physiologic changes associated with pregnancy.
What is considered “normal” swelling during pregnancy?
To answer this question it is important to have a basic understanding of the changes in maternal circulation during pregnancy.
Having this information helps make sense of the suggestions that will be offered at the end of this article.
As a rule, compliance with medical advice is far better when there is a scientific explanation or reason for why health problems or symptoms occur.
“Normal” swelling during pregnancy occurs when the result of the blood pressure within the blood vessels becomes greater than the osmotic pressure to keep fluid in your vessels.
As the fluid in your blood is allowed to leak or seep out of the vessels, it is sequestered in body tissues surrounding blood vessels.
This is the swelling we observe and is the reason you may notice “pitting edema” when you press on your swollen ankles.
This pitting resolves as the fluid redistributes.
Blood flow to the lower extremities is a high-pressure system.
Your arteries pump blood away from your heart. In addition, the forces of gravity push blood down when standing.
The low-pressure venous system is unable to effectively oppose this arterial pressure and return the blood back to the heart.
Veins use valves and muscular contractions to pump blood up your legs and back to the heart.
This is why simply elevating your legs can alleviate the swelling.
By just elevating your legs at night you can literally observe your swelling completely resolve by the next morning.
Why does swelling in your legs resolve overnight?
There two main facts that best explain why swelling during a pregnancy diminishes overnight.
The first is the physiology behind swelling and the second is the clinical observation:
The vascular pressure gradients that lead to the extravasation of fluid into the tissues is physiology.
This being said, the physiologic solution takes care of itself when you lie down to sleep at night.
It is simply because your legs and kidneys are at the same level as your heart.
Fluid in the tissues flows back into your blood vessels.
Your blood returns with this fluid to your heart and is then sent to your kidneys where the fluid is filtered out of your body all night long.
2. Clinical Signs:
So know that the fluid is able to be mobilized back to your heart what is the clinical observation?
Most new moms or pregnant women know the answer to this.
Urinating frequently throughout the night. T
he increased perfusion to the kidneys allows the extra fluid to be filtered out, only to start the entire process over the next day when your feet hit the ground in.
Elevate your legs whenever possible!
It is our hope that this information will help you understand why swelling increases during the day and resolves at night.
It is very important to remember that there are times when swelling occurs for other reasons that may be related to pregnancy complications.
This is not to say these complications do not have medical solutions, it is simply important that they are recognized and addressed to avoid worsening medical problems.