Approach to delay or regression in developmental milestones: Clinical sciences

Developmental milestones are behaviors and functional skills that children typically achieve by a specific age, in a predictable sequence. Developmental delay occurs when a child doesn’t meet an expected milestone on time, while developmental regression refers to the loss of previously acquired skills. Any delay or regression can impair a child’s ability to learn, communicate, and interact with others. Developmental delay and regression may impact one or more domains, including motor, language, cognitive, and social-emotional development.

Now, when a pediatric patient presents with a chief concern suggesting a developmental delay or regression... your first step is to obtain a focused history and physical exam and administer a validated developmental screening tool.

Keep in mind that general developmental screening tools are used for surveillance purposes, but if a caregiver has a specific concern, you should use a specific screening tool. Developmental screening tools assess age-specific behaviors and skills across all developmental domains, which include gross and fine motor, cognitive, language, and social-emotional. Remember to also perform hearing and vision screening.

Here’s a clinical pearl! Developmental screenings are routinely administered at the 9-, 18-, and 30-month well-child visits, and autism-specific screening is administered at the 18- and 24-month visits. However, screening can be administered at any point if a caregiver has a concern. Any child with a positive screen may benefit from a comprehensive developmental evaluation to assess developmental delay, even if caregivers report no specific concerns.

Okay, most patients present during early childhood, typically before the age of 5, with missed, delayed, or lost developmental milestones. Caregivers are often the first to report concerns about the child's development or behavior.

History may reveal risk factors for developmental delay or regression, including prematurity; low birth weight; and brain damage conditions, such as hypoxic-ischemic injury, intraventricular hemorrhage, and prenatal exposure to substances like alcohol. Be sure to ask about adverse childhood experiences, such as financial hardship, parental absence, or community violence. Finally, remember to ask about a family history of developmental disorders, as some cases of delay or regression have a genetic component.

Now, the developmental screening tool may identify concerns in one or more domains; while the vision or hearing screening may reveal vision or hearing impairment. With these findings, consider developmental delay or regression.

Time for some clinical pearls! When assessing your patient, remember that children with developmental disorders such as autism spectrum disorder may present with atypical behavior or communication styles rather than true developmental delay or regression.

Another important thing to keep in mind is that some children with developmental delays, and almost all children with developmental regression, have an underlying medical, genetic, or environmental cause.

For example, developmental regression can be caused by neurologic conditions, such as Tay-Sachs disease or seizure disorders; metabolic disorders, like inborn errors of metabolism or hypothyroidism; or genetic disorders, especially Rett syndrome, a neurodevelopmental disorder that mostly affects biological females and presents with progressive loss of language and motor skills.

Okay, once you consider developmental delay or regression, your next step is to arrange for a comprehensive developmental evaluation. This includes a detailed developmental and behavioral history, direct observation of behavior, and standardized testing of motor, language, and cognitive skills. Then, assess the developmental domain of concern.

Here’s a high-yield fact! Many children with delay or regression require additional diagnostic evaluation, especially if they present with abnormal exam findings. For example, if your patient has atypical facial features, consider genetic testing; and if you notice abnormal tone or reflexes, consider neuroimaging.

Let’s start with concerns from left to right, starting with the motor domain. History might be significant for hypoxic-ischemic brain injury, which often leads to cerebral palsy, one of the most common causes of motor delay.