Delayed doesn’t always mean safe—

Parents often feel relief when they hear their child’s bone age is delayed—“don’t worry, there’s plenty of time to grow.” But here’s the truth: a delayed bone age is not always reassuring. In fact, when the delay is two years or more, it may point to a medical condition like growth hormone deficiency (GHD) that requires careful evaluation.

As a pediatric endocrinologist, I want families to understand what a delayed bone age really means, when it signals something serious, and why you should not simply “wait and see.”

What Is a Delayed Bone Age?

Bone age refers to how mature your child’s bones are compared to their chronological age. It is measured through a simple X-ray of the hand and wrist, comparing the growth plates to standardized charts.

• Normal bone age: close to chronological age

• Delayed bone age: skeletal maturity lags behind (often by 1–2 years or more)

A delay in bone age is commonly seen in:

• Constitutional delay of growth and puberty (CDGP)

• Chronic illness or malnutrition

• Hormonal deficiencies, including growth hormone deficiency

• Genetic conditions such as achondroplasia

Why a Delayed Bone Age May Not Be a Good Thing

Many families are told, “Don’t worry, your child has plenty of time left to grow.” While sometimes true—especially in CDGP—not every case of delayed bone age is harmless.

📌 Key point:

• A mild delay (less than 1 year) can be normal.

• A significant delay (≥2 years) raises concern for growth hormone deficiency (GHD). You can read more about Growth Hormone deficiency here.

In children with GHD, bone age often lags two years or more, usually proportional to their slowed growth velocity and short stature. These children do not simply “catch up” without medical intervention.

The Research Connection: Delayed Bone Age and Growth Hormone Deficiency

Multiple studies confirm the association:

• Martin et al. highlight bone age as a central diagnostic tool in growth disorders .

• Allen & Cuttler note that a two-year bone age delay is characteristic of GHD and should trigger GH–IGF-1 axis testing .

• Vance & Mauras (NEJM) emphasize that bone age typically advances with GH therapy, underscoring its diagnostic role .

When bone age delay is significant, endocrinologists evaluate IGF-1 levels, perform GH stimulation tests, and rule out other causes before confirming diagnosis and treatment.

Why “Plenty of Time” Can Be Misleading

For children with GHD, “waiting” wastes critical years. The longer GH deficiency is untreated, the greater the risks of:

• Compromised adult height

• Weak bone density

• Low muscle mass and energy

• Delayed puberty

Early treatment works best. With GH therapy, bone age often “catches up,” further proving the link between delayed skeletal maturity and hormone deficiency.

"This is more than linear growth" - Dr. Toni Kim

When to Seek a Specialist Evaluation

If your child has:

• Short stature compared to peers

• Slowed growth velocity

• A bone age delayed by 2 years or more

👉 Don’t settle for “wait and see.” These are red flags that warrant a full evaluation by a pediatric endocrinologist. 

Worried about your child’s growth? Schedule a consultation today.

At Life Pediatric Endocrinology, we use advanced testing and personalized care to determine whether your child truly has “time to grow”—or needs timely intervention.

FAQs on Delayed Bone Age

1. Can a delayed bone age be normal?
Yes, mild delays (under 1 year) can occur in children with constitutional delay of growth and puberty (CDGP).

2. Does a delayed bone age always mean growth hormone deficiency?
No. But when the delay is two years or more, GHD becomes a strong possibility and testing is essential.

3. How is bone age measured?
A simple X-ray of the left hand and wrist compared to reference charts.

4. Can treatment help if my child has a delayed bone age due to GHD?
Yes. Growth hormone therapy often accelerates bone maturation and improves height outcomes.

5. Should parents be concerned if told “there’s plenty of time”?
Be cautious. Significant delays may signal underlying issues. Always seek a specialist’s evaluation.

About the Author

Dr. Toni Kim
is an internationally recognized pediatric endocrinologist specializing in growth and puberty. She leads Life Pediatric Endocrinology, helping families across the U.S. navigate complex growth conditions with cutting-edge, compassionate care.

References

1. Martin DD, Wit JM, Hochberg Z, et al.  The Use of Bone Age in Clinical Practice - Part 1. Horm Res Paediatr. 2011;76(1):1-9. doi:10.1159/000329372.

2. Palmert MR, Dunkel L. Delayed Puberty. N Engl J Med. 2012;366(5):443-53. doi:10.1056/NEJMcp1109290.

3. Satoh M, Hasegawa Y. Factors Affecting Prepubertal and Pubertal Bone Age Progression. Front Endocrinol. 2022;13:967711. doi:10.3389/fendo.2022.967711.

4. Allen DB, Cuttler L. Short Stature in Childhood — Challenges and Choices. N Engl J Med. 2013;368(13):1220-8. doi:10.1056/NEJMcp1213178.

5. Torlińska-Walkowiak N, et al. Skeletal and Dental Age Discrepancy in GHD and ISS. Clin Oral Investig. 2022;26(10):6165-6175. doi:10.1007/s00784-022-04566-y.

6. Vance ML, Mauras N.  Growth Hormone Therapy in Adults and Children. N Engl J Med. 1999;341(16):1206-16. doi:10.1056/NEJM199910143411607.