Do all people with restricted growth need genetic testing?

No. A diagnosis can often be made on clinical grounds using physical examination, imaging (such as X-rays), and family history. Genetic testing is offered when it would help clarify diagnosis, inform health monitoring, or guide family planning decisions.

Which specialists are involved in diagnosis?

Typically, a pediatrician, orthopedic specialist, endocrinologist, or geneticist may be involved. In some cases, a genetic counselor helps explain inheritance and testing options. Your GP can arrange specialist referrals.

Getting a Diagnosis

Q: Can restricted growth be detected during pregnancy?

Yes. During routine ultrasound scans, measurements of the fetus can be compared to typical growth patterns. If a baby is measuring smaller than expected, further imaging may be done. However, some forms of restricted growth cannot be reliably detected until after birth.

Q: What does genetic testing involve?

Genetic testing typically involves a blood sample (or sometimes a saliva sample) that is sent to a laboratory to look for changes in specific genes. Results take weeks to months and require discussion with a genetic counselor to understand what they mean.

By The Growth Conditions Guide Editorial Team · Updated July 2026 · 7 min read

A diagnosis of restricted growth can come before birth through prenatal imaging or after birth through physical examination, imaging, and sometimes genetic testing. Understanding the diagnostic process helps families know what to expect and when to ask questions.

Prenatal diagnosis

During routine pregnancy scans, typically around 20 weeks, ultrasound images are used to measure the size of the fetus. If measurements suggest the baby is smaller than expected for their stage of pregnancy, further imaging may be arranged. Some forms of restricted growth, particularly achondroplasia, may show characteristic bone features on ultrasound that can suggest a diagnosis.

However, not all forms of restricted growth can be reliably detected before birth. Some remain undetected until after delivery. If prenatal imaging raises concerns, a detailed ultrasound by a specialist, sometimes called a targeted scan, can provide more information. Some families may also choose non-invasive prenatal testing or genetic testing during pregnancy to confirm a diagnosis.

Clinical assessment at birth and beyond

After birth, healthcare professionals assess a baby's size, proportions, and bone features. Measurements of length, limb lengths, and body proportions are compared to typical growth patterns and to condition-specific references. A careful physical examination can often suggest which type of skeletal dysplasia is present based on characteristic features like limb proportions, spine shape, facial features, or joint positioning.

X-rays (radiographs) of bones are often done to see the pattern of bone development and confirm a suspected diagnosis. The specific pattern of bone changes is often distinctive enough to make a diagnosis without further testing.

Genetic testing

A blood or saliva sample can be sent to a genetics laboratory to look for changes in genes known to cause skeletal dysplasias. Results typically take several weeks to months. Genetic testing is particularly useful when a clinical diagnosis is unclear, when it would help predict health risks, when planning pregnancies, or when a person with restricted growth wants to know more about their specific condition and inheritance pattern.

Genetic testing is not compulsory. Some families find that clinical diagnosis and imaging are sufficient for their needs. Others choose testing for reassurance or to inform family planning decisions. A genetic counselor can help discuss whether testing makes sense for you and what results mean for you and your family.

Who is involved

Diagnosis typically involves your GP or general pediatrician as a starting point. Depending on circumstances, referrals may go to a pediatric endocrinologist (a specialist in growth and hormones), a pediatric orthopedist (a specialist in bones and joints), a geneticist, or a genetic counselor. In some areas, there are specialized skeletal dysplasia clinics that bring together specialists in one place.

You can ask your GP for a referral to a specialist if you have concerns about your child's growth or if you have been diagnosed with a condition and want more detailed information.

Growth monitoring

After diagnosis, regular monitoring of growth is important. Height, limb proportions, and spine are measured at routine visits and plotted on growth charts. This helps ensure that growth is following an expected pattern for the specific condition and can alert healthcare professionals to any concerns early. Some conditions require additional monitoring, such as hearing tests, eye exams, or spinal imaging, to watch for common complications.

When diagnosis is not clear

In some rare situations, a specific diagnosis may take time or remain uncertain even with testing. Genetic research is ongoing, and new genes and conditions are being identified. If this applies to you, a genetic counselor or specialist can discuss next steps, including the possibility of research testing or participation in research studies. You are not obligated to pursue diagnosis beyond what feels right for you and your family.

Common questions

Can restricted growth be detected during pregnancy?

Yes, some forms can be identified on prenatal ultrasound. However, not all types are reliably detected before birth. Detailed imaging or genetic testing during pregnancy can provide more information if ultrasound findings raise concerns.

What does genetic testing involve?

A blood or saliva sample is sent to a laboratory to look for genetic changes. Results take weeks to months. A genetic counselor helps explain what results mean for you and your family.

Do I need genetic testing?

No, it is not required. Clinical diagnosis using physical examination, imaging, and family history is often sufficient. Genetic testing is helpful when it would clarify diagnosis, inform health management, or guide family planning decisions.

How long does diagnosis take?

Clinical diagnosis can often be made at the first specialist visit using physical examination and imaging. Genetic testing takes several weeks to months. If a clear diagnosis is not possible immediately, follow-up appointments help build the picture over time.

Questions about diagnosis? Your healthcare team can answer questions about your specific situation. The Restricted Growth Association UK also provides support and information for families navigating diagnosis and beyond.

In summary

Diagnosis may occur before or after birth. Prenatal ultrasound can suggest some forms of restricted growth, while others are diagnosed through clinical assessment and imaging after birth. Genetic testing can confirm diagnosis and clarify inheritance patterns, but it is optional. Working with your healthcare team helps ensure proper monitoring and support tailored to your condition. For more background, see what restricted growth is or explore how growth charts are used to monitor development.