Anemia in Pregnancy: Causes, Symptoms, and Treatment

In short: Anaemia in pregnancy is diagnosed when haemoglobin is below 11 g/dl at the first visit, or below 10.5 in the second and third trimesters. Most cases are due to iron deficiency; other causes are folate deficiency and thalassaemia. It can cause tiredness, breathlessness and pallor, but often has no symptoms. It is treated with iron as directed by the doctor.

Anemia is a condition in which the body doesn’t have enough healthy red blood cells to carry oxygen to its tissues and organs. It is usually diagnosed when hemoglobin (Hb) levels drop below 11g/dl. If you’re expecting, understanding anemia can help you feel more confident about your prenatal care.

During pregnancy, the fluid part of your blood (plasma) increases by about 40-50%, while the number of red blood cells rises by only about 20-30%. This extra fluid can dilute the blood, causing a mild, expected drop in Hb to around 11.5g/dl — this is considered normal. True anemia during pregnancy is diagnosed when Hb is below 11g/dl in the first trimester or below 10.5g/dl in the second and third trimesters, and after delivery when Hb is less than 10g/dl.

What Causes Anemia During Pregnancy?

Physiological Anemia

This mild, expected form of anemia is caused by the natural increase in blood volume, which dilutes the concentration of red blood cells. It is a normal part of a healthy pregnancy.

Iron Deficiency Anemia

This is the most common cause of anemia during pregnancy. It happens when a woman doesn’t have enough iron stored in her body before becoming pregnant, since the growing baby relies on her red blood cells for development.

Vitamin B12 Deficiency

Vitamin B12 plays a key role in forming red blood cells, so a deficiency can lead to anemia. This is more common in vegans (those who avoid animal products). Adding foods like milk, meat, eggs, and poultry to your diet can help prevent this deficiency.

Folic Acid Deficiency

Folic acid works alongside iron to support healthy cell growth. It is often linked with iron deficiency anemia, since both nutrients are found in similar food sources.

Thalassemia

Thalassemia is an inherited (autosomal recessive) blood disorder caused by missing or altered genes involved in hemoglobin production. This can weaken and destroy red blood cells. Women who carry the thalassemia gene may have no symptoms before pregnancy but can develop symptoms during it.

Carriers often have slightly low hemoglobin with small red cells, which can be mistaken for iron deficiency; iron should only be given if your ferritin test shows that your iron stores are actually low. In these cases, it’s recommended that the father also be tested, and couples may benefit from genetic counselling and prenatal testing to check the baby’s health. Chorionic villus sampling (usually performed around 11 weeks) involves testing a small sample of placental tissue, while amniocentesis, done around 16 weeks, involves testing a small amount of the amniotic fluid surrounding the baby.

Sickle Cell Anemia

Sickle cell anemia is an inherited blood disorder in which red blood cells become stiff and sticky when they lose oxygen. These cells can clump together, blocking blood vessels and causing pain along with other complications. While normal red blood cells live about 120 days, sickle cells survive only around 15 days and are more likely to be broken down in the spleen.

Risks of Sickle Cell Anemia for Pregnant Women

• Infections (including urinary tract and lung infections)
• Gallbladder stones
• Heart failure

• Painful crises and acute chest syndrome - Pre-eclampsia and blood clots (thrombosis) Women with sickle cell disease should be cared for by a specialist team, take high-dose folic acid (5 mg daily) and are usually advised to take low-dose aspirin from 12 weeks.

Risks of Sickle Cell Anemia for the Baby

• Miscarriage
• Preterm labor
• Intrauterine growth restriction
• Low birth weight
• Stillbirth

Less Common Causes of Anemia in Pregnancy

• Leukemia
• Hemolytic anemia
• Gastrointestinal (GI) bleeding

Symptoms of Anemia

• Fatigue
• Shortness of breath
• Pale skin, lips, nails, or palms
• Rapid heartbeat (tachycardia)

Tests Used to Diagnose Anemia During Pregnancy

• Hemoglobin level
• Ferritin level (a level below 30 mcg/l means your iron stores are low and iron treatment is recommended, even if hemoglobin is still normal)
• Mean cell volume (MCV) — a value below 80 (small red cells) suggests iron deficiency or thalassemia trait, so it is interpreted together with ferritin and hemoglobin electrophoresis
• Hemoglobin electrophoresis

Treatment of Anemia in Pregnancy

Treatment depends on the underlying cause and type of anemia, and generally includes:

• Identifying the type of anemia and treating the root cause
• Dietary guidance and nutrition support
• Iron tablets (usually one dose a day or every other day, taken on an empty stomach or with vitamin C-rich juice, not with tea, coffee, milk or calcium), with a blood test after 2-4 weeks to confirm improvement; intravenous (drip) iron if tablets do not work, are not tolerated, or anemia is found late in pregnancy; and folic acid or vitamin B12 when these are low

Possible Complications of Anemia in Pregnancy

Untreated anemia during pregnancy can carry serious risks for both mother and baby, which is why early detection and proper care are so important. If you have concerns about anemia or your prenatal health, the team at Dr. Najeeb Layyous’s clinic is here to guide you through personalized evaluation and care.

Dr Najeeb Layyous F.R.C.O.G

Consultant Obstetrician, Gynecologist and Infertility Specialist