What are the symptoms of folate deficiency in pregnancy?

Symptoms of Folate Deficiency in Pregnancy

Folate deficiency during pregnancy primarily manifests as megaloblastic anemia and can lead to serious birth defects, particularly neural tube defects (NTDs) in the developing fetus. 1

Maternal Symptoms of Folate Deficiency

• Megaloblastic anemia - characterized by:

  • Fatigue and weakness
  • Pallor
  • Shortness of breath
  • Tachycardia
  • Headaches
  • Dizziness or lightheadedness 1

• Neurological manifestations:

  • Peripheral neuropathy
  • Irritability
  • Depression
  • Cognitive impairment 1

• Gastrointestinal symptoms:

  • Glossitis (inflammation of the tongue)
  • Anorexia
  • Nausea
  • Diarrhea 1

Fetal Consequences of Maternal Folate Deficiency

The most severe consequences of folate deficiency affect the developing fetus:

• Neural tube defects - occur within the first 28 days after conception (often before pregnancy is recognized):

  • Anencephaly - partial or complete absence of skull bones with minimal brain tissue; almost always fatal before or shortly after birth 2
  • Spina bifida - failure of vertebral arches to close over the neural tube, exposing the spinal cord and nerves; leads to moderate to severe disabilities 2
  • Encephalocele - protrusion of brain tissue through the skull, most often in the occipital region 2

• Other potential birth defects:

  • Congenital heart defects 3
  • Orofacial clefts 2
  • Limb and renal anomalies 2

• Pregnancy complications:

  • Low birth weight 3, 4
  • Preterm birth 3

Risk Factors for Folate Deficiency in Pregnancy

• Low socioeconomic status 4
• Unplanned pregnancy 4
• Smoking 4
• Lower educational level 4
• Poor dietary intake of folate-rich foods
• Lack of folic acid supplementation before and during early pregnancy 4

Laboratory Findings

• Red blood cell (RBC) folate concentration below 400 ng/ml in first trimester (found in 39% of women) 4
• RBC folate concentration below 300 ng/ml in first trimester (found in 15% of women) indicates significant deficiency 4
• Elevated homocysteine levels (a metabolic consequence of folate deficiency) 1

Prevention of Folate Deficiency

To prevent folate deficiency and its consequences:

• Women of childbearing age should consume 400 μg (0.4 mg) of folic acid daily throughout their reproductive years 2
• Women who have had a prior NTD-affected pregnancy should take 4 mg of folic acid daily starting at least 1 month (preferably 3 months) before conception 2
• Supplementation should continue through the first trimester of pregnancy 2
• Total daily intake should not exceed 1000 μg (1.0 mg) unless prescribed by a physician, to avoid masking vitamin B12 deficiency 2

Clinical Implications

Early detection and treatment of folate deficiency is crucial to prevent serious maternal and fetal complications. The critical period for neural tube closure occurs within the first 28 days after conception, often before a woman knows she is pregnant 2, 5. This underscores the importance of adequate folate intake for all women of childbearing potential, not just those actively planning pregnancy.

Given that approximately 39% of first-trimester pregnant women may have suboptimal folate status to prevent NTDs 4, healthcare providers should actively screen for risk factors and symptoms of folate deficiency and ensure appropriate supplementation.