Congenital Hypothyroidism in Newborns – Causes & Treatment
“What is Congenital Hypothyroidism?”
Congenital hypothyroidism (CH) is a condition in which a newborn lacks sufficient thyroid hormones,
which are essential for growth and brain development.
If detected early and treated properly, normal development is possible.
However, if left untreated, it can lead to intellectual disabilities and growth retardation.
Today, we will discuss the causes, symptoms, treatment, and prevention of CH in newborns.
📌 Introduction
Congenital hypothyroidism (CH) is a condition where newborns are born with low thyroid hormone levels,
affecting approximately 1 in 2,000–4,000 newborns worldwide.
✅ Thyroid hormones play a crucial role in brain development and overall growth.
✅ Early detection and appropriate treatment are essential for normal development.
💡 This article will explore the causes, symptoms, diagnosis, and treatment of CH in newborns.
Causes and Risk Factors of Congenital Hypothyroidism
Congenital hypothyroidism (CH) occurs when a newborn lacks adequate thyroid hormone production,
which can result from structural abnormalities or hormone synthesis defects.
1️⃣ Main Causes of Congenital Hypothyroidism
✔ Thyroid Dysgenesis (Agenesis or Hypoplasia)
– Most common cause (~85% of CH cases)
– Thyroid gland is absent (agenesis) or underdeveloped (hypoplasia)
– May be caused by genetic or environmental factors
✔ Ectopic Thyroid Gland
– The thyroid is located in an abnormal position, preventing proper hormone production
✔ Thyroid Dyshormonogenesis (Hormone Synthesis Defects)
– Occurs in 10–15% of CH cases
– Mutations in thyroid peroxidase (TPO) or other enzymes prevent proper hormone production
– Often inherited (autosomal recessive genetic disorder)
✔ Iodine Deficiency or Excess
– Insufficient iodine intake during pregnancy → Thyroid hormone deficiency
– Excess iodine (medications, contrast agents) → Inhibits thyroid function
✔ TSH Receptor Abnormalities
– Defective thyroid-stimulating hormone (TSH) receptors prevent normal thyroid stimulation
2️⃣ Risk Factors for Congenital Hypothyroidism
✔ Female Gender (CH is 2x more common in females than males)
✔ Family History (Genetic Factors)
– Higher risk if parents or siblings have thyroid disorders
✔ Maternal Thyroid Disorders
– Mothers with hypothyroidism or autoimmune thyroid disease
– Use of antithyroid medications (PTU, Methimazole) during pregnancy
✔ Iodine Imbalance
– Living in iodine-deficient regions increases risk
– Excess iodine intake (seaweed, contrast agents) may also suppress thyroid function
✔ Multiple Births (Twins, Triplets, etc.)
– Higher risk due to limited nutrients during pregnancy
✔ Preterm or Low Birth Weight Infants
– Thyroid function may not be fully developed in premature infants
💡 Summary of CH Causes & Risk Factors
✔ Thyroid gland underdevelopment or absence
✔ Hormone synthesis defects (genetic mutations)
✔ Iodine deficiency or excess
✔ Maternal thyroid disease or medication exposure
✔ Preterm birth or multiple gestation
Early detection and treatment are essential for normal development.
Symptoms and Diagnosis of Congenital Hypothyroidism
Congenital hypothyroidism (CH) may not show obvious symptoms at birth,
but delayed treatment can severely impact brain development and growth.
Early diagnosis is essential for preventing complications.
1️⃣ Key Symptoms of Congenital Hypothyroidism
✔ Early Symptoms (Within the First 2 Weeks)
– Lethargy → Baby appears unusually inactive and weak
– Hypothermia → Body temperature is lower than normal
– Feeding difficulties → Weak sucking reflex and prolonged feeding time
– Prolonged jaundice → Newborn jaundice lasting more than 2 weeks
– Constipation → Infrequent bowel movements with firm stools
✔ Symptoms in More Advanced Cases
– Enlarged tongue (Macroglossia) → Tongue appears thick and protrudes from the mouth
– Flat nasal bridge → Puffy facial features and characteristic facial appearance
– Umbilical hernia → Bulging belly button
– Low muscle tone (Hypotonia) → Weak, floppy arms and legs
– Hoarse cry → Low-pitched, hoarse crying sound
⚠ Symptoms may not be immediately noticeable,
so newborn screening tests are critical for early detection.
2️⃣ Diagnostic Methods for Congenital Hypothyroidism
✔ Newborn Screening Test
– Blood sample taken from the baby’s heel 48–72 hours after birth
– Measures TSH (Thyroid-Stimulating Hormone) and T4 (Thyroxine) levels
– High TSH + Low T4 → Further diagnostic tests required
✔ Serum Thyroid Function Test
– Increased TSH + Decreased T4 confirms hypothyroidism
– Additional tests may include thyroid peroxidase (TPO) antibody testing
✔ Thyroid Ultrasound & Radioiodine Scan
– Determines if the thyroid gland is present or underdeveloped
– Evaluates iodine uptake and hormone production ability
✔ Genetic Testing (Optional)
– Used in familial cases to identify mutations in PAX8, TSHR, or TPO genes
💡 Summary of CH Symptoms & Diagnosis
✔ Early Symptoms: Low temperature, lethargy, feeding issues, prolonged jaundice, constipation
✔ Advanced Symptoms: Large tongue, flat nasal bridge, umbilical hernia, low muscle tone, hoarse cry
✔ Diagnosis: Newborn screening (TSH & T4 tests), blood tests, thyroid ultrasound
✔ Early detection is crucial! → Delayed treatment can result in developmental delays & intellectual impairment
Congenital hypothyroidism often presents with mild symptoms initially,
so regular newborn screening is essential for early detection and intervention.
Treatment and Management of Congenital Hypothyroidism
Congenital hypothyroidism (CH) is a treatable condition,
and early intervention ensures normal growth and development.
The key to treatment is immediate thyroid hormone replacement.
1️⃣ Treatment Options for Congenital Hypothyroidism
✔ Levothyroxine (L-thyroxine, LT4) Hormone Replacement Therapy
– First-line treatment: Levothyroxine (LT4) → Replaces missing thyroid hormones
– Recommended dosage: 10–15 mcg/kg/day in neonates
– Administration:
– Given once daily on an empty stomach (avoid milk, iron, and calcium supplements)
– Tablet can be crushed and mixed with water before feeding
✔ When to Start Treatment
– Within the first 2 weeks after birth → Best for brain development
– Delayed treatment (>1 month) → Increases risk of intellectual impairment
✔ Monitoring and Follow-up
– TSH & T4 blood tests every 2–4 weeks initially
– Regular monitoring until at least age 3 to ensure normal hormone levels
2️⃣ Long-Term Management of CH
✔ Determining the Need for Lifelong Treatment
– Some infants may have transient hypothyroidism
– Thyroid function re-evaluation at age 3 to assess need for continued LT4 therapy
– If function remains low, lifelong treatment is necessary
✔ Regular Growth and Development Monitoring
– Assess cognitive and motor skills every 6–12 months
– Ensure normal language and motor development
– If delays are detected, referral to speech or physical therapy may be needed
✔ Nutritional and Lifestyle Adjustments
– Avoid excessive iodine intake (seaweed, kelp, iodine-rich foods)
– Do not take iron or calcium supplements with LT4 (reduces absorption)
💡 Summary of CH Treatment & Management
✔ Early treatment is essential → Start LT4 within 2 weeks
✔ Daily levothyroxine therapy → Maintains normal thyroid function
✔ Regular blood tests (TSH & T4 monitoring) → Evaluates treatment effectiveness
✔ Long-term neurodevelopmental follow-up → Ensures proper cognitive and physical growth
✔ Proper nutrition and medication timing → Avoid excess iodine and mineral interactions
Congenital hypothyroidism can be effectively managed with early diagnosis and consistent treatment.
Without intervention, developmental delays and permanent cognitive impairment may occur,
making continuous monitoring and care essential.
Prevention and Conclusion for Congenital Hypothyroidism
Congenital hypothyroidism (CH) is a manageable condition
if diagnosed and treated early. While it cannot always be prevented,
certain measures can help reduce the risk and improve long-term outcomes.
1️⃣ How to Prevent Congenital Hypothyroidism
✔ Maintaining Proper Iodine Intake During Pregnancy
– Iodine is essential for thyroid hormone production, but excess or deficiency can cause problems
– Recommended intake for pregnant women: 250–300 mcg/day
– Moderate consumption of iodine-rich foods (seaweed, kelp, fish)
✔ Maternal Thyroid Health Management
– Pregnant women with hypothyroidism (Hashimoto’s disease) should have proper monitoring & treatment
– If taking antithyroid medications (PTU, Methimazole), dosage should be adjusted by a physician
✔ Newborn Screening (TSH & T4 Testing)
– Blood test within 48–72 hours after birth (mandatory for all newborns)
– Immediate follow-up testing if thyroid dysfunction is suspected
✔ Monitoring High-Risk Infants
– Babies with a family history of thyroid disorders, preterm birth, or low birth weight need additional screening
– Multiple birth infants (twins, triplets) should have regular thyroid function checks
2️⃣ Long-Term Management After CH Diagnosis
✔ Regular Thyroid Function Testing (TSH & T4 Monitoring)
– Testing at 2–4 weeks, 6 months, 1 year, and annually afterward
– At age 3, thyroid function is reassessed to determine if lifelong treatment is needed
✔ Growth and Neurodevelopmental Monitoring
– Regular follow-ups with pediatric endocrinologists and developmental specialists
– Monitor cognitive and motor skills, especially in infants diagnosed late or with severe CH
✔ Consistent Medication & Lifestyle Adjustments
– Daily Levothyroxine (LT4) treatment must be continued without interruption
– Avoid taking iron and calcium supplements with thyroid medication (reduces absorption)
– Regulate iodine intake to prevent excess or deficiency
🔥 Conclusion & Key Takeaways
Congenital hypothyroidism can be effectively managed with early diagnosis and proper treatment.
However, delayed treatment may lead to permanent intellectual and growth impairments.
🎯 Key Strategies for CH Prevention & Management
✔ Ensure proper maternal iodine intake
✔ Monitor maternal thyroid health during pregnancy
✔ Newborn screening (TSH & T4 tests) within the first 48–72 hours
✔ Regular thyroid function monitoring → Evaluate need for lifelong treatment at age 3
✔ Monitor neurodevelopment to prevent delays
💡 With early intervention and proper management, children with CH can lead normal, healthy lives.
Parental awareness and medical support are crucial for the child’s future well-being. 😊
