# Effect of timely diagnosis and treatment on growth and body proportionality of children with congenital hypothyroidism

## TL;DR

This study shows that early treatment of congenital hypothyroidism in children improves growth and body proportions, while delayed treatment leads to significant developmental issues.

## Contribution

The study demonstrates the critical impact of early treatment timing on growth outcomes and skeletal proportions in children with congenital hypothyroidism.

## Key findings

- Late-treated children had higher rates of severe stunting, underweight, and microcephaly compared to early-treated children.
- Skeletal disproportionality was more common in late-treated children, as shown by upper-to-lower segment ratios and Manouvrier’s Index.
- Early treatment within the first 3 months significantly improves growth and neurocranial development outcomes.

## Abstract

Congenital hypothyroidism (CH) is a preventable cause of growth and neurodevelopmental deficits. In India, lack of universal newborn screening (NBS) delays diagnosis. This study examines how treatment timing influences growth, nutrition, and body proportionality in children with CH.

This cross-sectional study included 66 children with CH, aged under 5 years, receiving Levothyroxine(LT4) therapy for one year. Age and sex-matched 64 healthy children were also enrolled. Children with CH were stratified into early-treated (<3months) and late-treated (>3months) groups. Anthropometric measurements were converted to Z-scores using WHO standards. Body proportionality was assessed using: height–arm span difference, upper segment-to-lower segment (US: LS) ratio, Manouvrier’s Indice Skélique (MIS). MIS classifies skeletal proportions as brachyskelia (short legs, long trunk; score ≤84.9), mesatyskelia (intermediate; 85.0–89.9), and macroskelia (long legs, short trunk; ≥90).

Children with CH had significantly lower height-for-age (HAZ −2.31 ± 1.32 vs. −0.41 ± 0.96), weight-for-age (WAZ −1.98 ± 1.41 vs. −0.36 ± 1.02), and head circumference-for-age (HCZ −1.52 ± 1.28 vs. −0.21 ± 0.89) Z-scores compared with healthy controls (all p < 0.001). Stunting (HAZ < −2 SD) was present in 53% of children, while underweight (WAZ < −2 SD) was observed in 36.4%. Late-treated children had a higher prevalence of severe stunting (67.7% vs. 11.4%), severe underweight (29.0% vs. 2.9%), and microcephaly (35.5% vs. 8.6%) compared with early-treated children (p < 0.05). Disproportionate stature was observed in 71.0% of late-treated children compared with 42.9% of early-treated children (p < 0.05). US: LS ratio and Manouvrier’s Index further confirmed greater skeletal disproportionality in late-treated children compared with early-treated children (p < 0.05).

Delayed treatment in CH significantly impairs growth, increases skeletal disproportionality, and adversely affects neurocranial development. Early initiation of therapy—ideally within the first 3 months—is essential. These findings highlight the need for newborn screening in India.