DoctorSpeak: Why screening newborns for thyroid is a must

Congenital hypothyroidism (CH) affects nearly 1 in 1,000 to 3,500 newborns in India. With around 26 million annual births, at least 10,000 babies are born every year with this condition, almost 27 babies every day, that is one baby every hour. However, the encouraging part is that if diagnosed and treated within the first two weeks of birth, these children can grow up with normal intelligence and physical development. However, delayed treatment can reduce IQ by 30–50 points and perhaps delay in some developmental milestones.

What is congenital hypothyroidism

Congenital hypothyroidism is a condition present at birth in which a baby’s thyroid gland does not produce enough thyroid hormone (thyroxine or T4). This hormone is critical for brain development, growth, bone maturation, muscle strength, and metabolism, particularly in the first few weeks after birth. Without sufficient thyroid hormone during this vital window, irreversible brain damage can occur. The tragedy is that most babies with CH look completely healthy and normal at birth.

All newborns are at equal risk of having CH. This condition has nothing to do with a premature birth or a family or genetic history of thyroid in the mother or other family members.

Hence, a majority of babies with CH have no risk factors. This is why universal newborn screening — not selective testing — is essential. In a recent case, a healthy-looking baby girl underwent routine heel-prick screening at 48 hours of birth. Though she had showed no symptoms, her TSH levels were quite high. Confirmatory tests revealed a low T4, and the treatment began within 10 days. Today, she is healthy with completely normal development. Early screening made a big difference.

Critical window

The most crucial period is the newborn stage (0–28 days). Brain development is fastest in the first two weeks of life. Mandatory newborn screening within 48–72 hours after birth is, therefore, non-negotiable.

Beyond the neonatal phase

— Infants (0–2 years): Rapid brain growth continues. Any delay in sitting, walking, speech, or growth warrants evaluation if screening was missed at birth.

— Toddlers and preschool children: Unexplained developmental delay, learning difficulties, persistent constipation, or poor growth should prompt thyroid testing.

— The only point to remember: The only preventive screening window is the immediate period after birth. Waiting for symptoms to appear defeats the purpose of protection.

Symptoms can be often missed

Early signs are subtle and may appear weeks later. These may include:

— Excessive sleepiness

— Feeding difficulties and constipation

— Prolonged jaundice

— Large tongue

— Hoarse cry

— Puffy face

— Cold, dry skin

By the time these signs become obvious, brain development may already be compromised.

In another case, parents of a baby boy, who missed newborn screening, at 3 weeks noticed the baby’s excessive sleepiness and constipation. Blood tests confirmed severe hypothyroidism. Although the treatment began immediately, the delay had already resulted in developmental lag, requiring long-term therapy. The difference between early and late diagnosis can be lifelong care and support.

How to detect congenital hypothyroidism

The most important test is the newborn heel-prick screening, ideally performed 48-72 hours after birth. A few drops of blood can measure Thyroid Stimulating Hormone (TSH). If it’s elevated, confirmatory tests — Serum TSH and Free T4 — establish the diagnosis.

Imaging, such as a thyroid scan, may sometimes be done to assess the gland development. However, the treatment should never be delayed while awaiting imaging results.

When to start treatment

The treatment should ideally begin within the first 14 days of birth. It involves daily oral thyroid hormone replacement — a safe, affordable, and highly effective medication.

Regular blood tests can monitor the TSH and T4 levels to ensure proper dosing. Initially, monitoring is frequent, then spaced out as the child grows. In many children, CH is permanent and requires lifelong treatment. In some cases, it may be temporary, and doctors reassess thyroid function around three years of age. With timely and consistent treatment, children can lead completely normal lives.

Can congenital hypothyroidism be prevented

Most cases cannot be prevented but parents-to-be should discuss mandatory newborn screening before delivery. Prevention may not always be possible, but preparation ensures protection.

The bottom line

Congenital hypothyroidism is one of the most preventable causes of intellectual disability in children. A simple heel-prick test in the first few days of birth can safeguard a child’s brain forever.

— The writer is president, National Neonatology Forum (Karnataka Chapter)

Newborn heel-prick screening blood test, performed 48-72 hours after birth, should be made mandatory in India. Istock

Why early testing is vital

— Diagnosis is simple

— Treatment is affordable

— Outcomes are excellent

In absence of testing

— Intellectual disability may occur

— Growth may be affected

— Lifelong support may be required

A baby with CH may look perfectly normal — but appearances can be deceiving. It is our responsibility to ensure every newborn is screened. An early diagnosis can ensure normal life for the affected infant.

FACTCHECK

Congenital Hypothyroidism is a leading, preventable cause of intellectual disability in India, affecting approximately 1 in 1,031 to 3,500 new-borns. The prevalence in India is higher than in many developed nations. Early screening within 2-4 days of birth is critical, using Levothyroxine to prevent severe cognitive impairment. Studies from South India show incidences ranging from 1 in 727 to 1 in 2,640. CH can be caused by absent or underdeveloped thyroid gland and iodine deficiency. There is no nationwide, universal new-born screening in India. Many cases are missed due to a lack of awareness and infrastructure.