Anemia is common during pregnancy. In the third trimester, it may require iron supplements or blood transfusions to help reduce the chances of premature birth, low birth weight, or a longer hospital stay after delivery.

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Anemia is when there are not enough red blood cells to carry oxygen to all the tissues of the body. It is especially concerning in the third trimester of pregnancy due to an increased risk of premature birth and other serious health complications.

Although anemia is fairly common in pregnancy, it can lead to complications.

Potential risks from anemia include an increased risk of preterm birth and low birth weight. Other potential risks include:

One 2017 study found that severe anemia during the third trimester was associated with longer hospital stays after delivery. Researchers found that iron supplements or other anemia treatments may help prevent this.

If you have anemia in the third trimester of pregnancy, it can be especially difficult. According to a 2019 research review, conditions that may occur more frequently in pregnancies with anemia in the third trimester include:

  • premature delivery (delivery before 37 weeks)
  • low birth weight
  • babies who are small for gestational age
  • postpartum depression
  • increased risk of neonatal death

Anemia is frequently diagnosed during the routine blood tests done throughout pregnancy.

If your doctor suspects you have anemia, they may order a blood test to check whether you have low red blood cell counts at any point during your pregnancy — including the third trimester.

During pregnancy, your body works hard to nourish your growing baby. To get sufficient nutrients to the baby, your blood volume increases by about 20% to 30%.

The overall blood volume increases during pregnancy, but the plasma or liquid volume increases more than the red blood cell volume. The result is a lower overall percentage of red blood cells.

Another cause of anemia during pregnancy is low iron, folic acid, or vitamin B12 levels. If your doctor diagnoses anemia, they will investigate further to determine the cause and closely monitor how severe your anemia becomes.

Medical treatment

For mild anemia, your doctor will likely recommend taking an iron or prenatal supplement.

For severe anemia, your doctor may suggest a blood transfusion to help reduce the risks of anemia.

What you can do at home

In addition to taking an iron or prenatal supplement, you can also improve your iron and folic acid levels by eating a nutritious, balanced diet full of iron-rich foods.

If you are getting your iron from plant-based sources, you may want to consider pairing the iron source with a food high in vitamin C to help increase absorption.

Should I take iron supplements even if I don’t currently have anemia?

Although you can buy iron supplements at many stores without a prescription, always talk with your OB-GYN or another healthcare professional before taking an iron supplement.

Too much iron in the body can cause serious health problems.

If my symptoms aren’t improving after starting an iron supplement, does this mean I need a higher dose?

Your body must replace red blood cells before symptoms improve. It can take several weeks for red blood cell levels to rise and symptoms to disappear.

If you’re not seeing improvement after several weeks, you can talk with your doctor about getting your iron levels checked again. Your doctor can then help you to decide on appropriate next steps.

What is restless legs syndrome?

Restless legs syndrome is a disorder that causes extreme discomfort when sitting, lying down, and often during sleep. It causes the urge to move your legs or even get up and move around.

Restless legs syndrome is common in people with iron deficiency during pregnancy. Iron supplementation under a doctor’s supervision may relieve it.

Many people develop anemia at some point during pregnancy. This is often due to low iron stores and increasing blood volumes.

If anemia becomes severe, it can potentially lead to complications like preterm delivery and low birth weight. Your doctor may recommend an iron supplement or blood transfusion to manage your anemia and prevent complications.