The demand for iron increases during pregnancy to meet the demands of the growing fetus and placenta, as well as maternal adaptations to pregnancy.
Let’s start with the basics.
Your body uses iron to make hemoglobin – a substance in red blood cells – which transports oxygen throughout your body. When you are pregnant, your body also supplies blood and oxygen to your baby too, so the need for iron increases to keep up with the increase in blood supply.
Daily iron requirements vary depending on age and gender. Males aged 18+ and women over 50 need 8.7mg daily. However, it’s recommended that women who are having monthly periods have 14.8mg.
FACT: It is estimated that 30-40% of pregnant women in industrialized countries are iron deficient.
Importance of Iron when Pregnant Woman
Iron deficiency is especially common in women with a history of low iron, those following plant-based diets, women who experienced heavy menstrual flow prior to pregnancy, in a multiple pregnancy (twins, triplets etc.), women who are having pregnancies close together, and those experiencing issues with dietary iron absorption e.g. IBD, Coeliac Disease.
Getting enough iron from food when you're pregnant can be difficult, even if you're carefully trying to add iron to your diet. This is especially true if you do not consume iron-rich meats or poultry. Be sure to tell your OBGYN if you are following a plant-based diet so they can keep a closer eye on your iron and hemoglobin levels.
It is very common for women to develop iron deficiency during pregnancy. This is because your body needs extra iron so that your baby has a sufficient blood supply and receives all of the necessary oxygen and nutrients. Many pregnant women require an iron supplement during pregnancy and breastfeeding.
What foods are high in iron?
You can find iron in meat, poultry, and plant-based foods as well as in supplements. There are two types of iron in foods.
- Heme iron is the type your body absorbs best, so it’s a good idea to especially focus on these foods to help keep your iron levels up during pregnancy. You get heme iron in beef, chicken, turkey, pork, and fish.
- Non-heme iron is the other type, which you can find in beans, vegetables, tofu, dried fruits, eggs, whole grains and ready-to-eat-cereals that have added iron.
Iron-rich foods include:
- dark-green leafy vegetables, such as watercress, spinach, and curly kale
- iron-fortified bread
Interestingly, what you consume with your iron can affect how well your body absorbs the mineral. While you eat foods that are high in iron, have them with foods that contain Vitamin C, such as tomatoes and oranges. Vitamin C helps your body absorb nonheme iron better when you eat both at the same meal.
On the other hand, certain drinks and foods prevent your body from absorbing iron. These include coffee, tea, whole grains, and dairy products. Try not to eat these foods in the same meal as foods high in iron. For example, instead of having coffee or tea with your breakfast cereal, have a glass of orange juice.
However, once a woman becomes iron deficient during pregnancy, dietary sources of iron will be insufficient to replenish levels and oral iron supplementation is recommended.
Risks of iron deficiency in pregnancy
Pregnant women with iron deficiency have an increased risk of developing complications, particularly during and after the birth. They may also develop postnatal depression.
Research suggests that babies born to mothers that are iron deficient are more likely to:
- be born prematurely (before week 37 of the pregnancy)
- have a low birth weight
Iron deficiency can lead to fatigue, light-headedness, and dizziness. When you add these on top of typical pregnancy symptoms it's a double whammy. So be sure to mention any unusual symptoms, including exhaustion that seriously disrupts your day to your doctor.
Taking iron supplements during pregnancy increases hemoglobin levels, and halves the risk of the mother becoming iron deficient during pregnancy.
However, not all iron supplements are the same, and many women experience unpleasant side-effects (such as constipation or nausea) from conventional iron pills. If you are choosing an iron supplement, be sure to choose one that is kind on your stomach, while providing the absorption you need.
UN Children’s Fund, UN University, World Health Organization. Iron deficiency anemia: assessment, prevention, and control. A guide for program managers, 2001.
Scientific Advisory Committee on Nutrition. Iron and health. 2010. www.sacn.gov.uk Accessed March 2019.
Abbaspour N et al. Review on iron and its importance for health. J Res Med Sci 2014; 19 (2): 164-174. Soppi ET. Iron deficiency without anemia – a clinical challenge. Clinical Case Reports 2018; 6 (6): 1082-1086.
Goddard AF et al. Guidelines for the management of iron deficiency anemia. Gut 2011; 60: 1309-1316.