Developmental milestones (childhood): Clinical sciences

Developmental milestones are behaviors and functional skills that children are expected to acquire by a specific age. These milestones are typically achieved in a predictable sequence and are divided into five major categories: gross motor development, which relates to the movement of large muscles; fine motor development, which relates to the movement of small muscles; cognitive development, which includes reasoning, memory, and problem-solving; social-emotional development, which describes attachment to and interactions with others; and finally, language development, which consists of receptive and expressive communication.

Your overall goal is to assess the child’s developmental milestones according to their age, using the caregiver’s report as well as direct observation. Understanding normal developmental milestones will help you recognize when a child is at risk for a developmental delay that would benefit from a more detailed evaluation and early intervention services.

Now, when a pediatric patient presents for assessment of their developmental milestones, first, obtain a focused history and physical exam. During the history, be sure to review birth history, including gestational age and birth weight, as both prematurity and low birth weight are associated with developmental delays.

Also ask about family history of developmental delays, as some developmental disorders such as autism spectrum disorder have a genetic component. You should also take an interval history to determine what new skills the child has learned since the last clinic visit.

Additionally, observe the interactions between the child and their caregiver, and ask the caregiver if they have any concerns about their child’s development.

Now, here’s a clinical pearl to keep in mind! Caregivers spend the most time with their child and are often the first to notice when something isn’t quite right. Whenever a caregiver is concerned about their child’s development, be sure to investigate further!

When it comes to the physical exam, check reflexes, assess muscle tone, and test their balance. Additionally, use this time to observe how the child interacts with the world, with their caregiver, and with you, as this can help you gauge the child’s development.

Once you are done with history and physical exam findings, it’s time to assess developmental milestones, based on the child’s age. Let’s start by discussing expected milestones for a three- year-old. By this age, the child has achieved new gross motor skills, including the ability to walk up stairs with alternating feet and without using a handrail. A three-year-old can also balance on one leg, walk heel-to-toe when asked, pedal a tricycle, and catch a ball. Fine motor skills are more advanced, and now they are able to draw circles and crosses, and can string small items together, like beads or macaroni.

Cognitive skills have become more advanced, and the child now can eat independently, and are toilet trained. They can also put on their own shoes, match letters and numbers, and understand comparisons, like long versus short, or hot versus cold. From a social-emotional standpoint, they now know their gender and their age, and they can point to themselves in pictures, take turns with others, and enjoy imaginative play. Language milestones include the ability to use a vocabulary of over 200 words, make three-word sentences, and use plurals. The three-year-old child is also known for asking all the “W” questions, like who, what, when, where, and why. To strangers, about 75% of their speech is now intelligible.

While you assess your patient for their developmental milestones, keep an eye out for age-specific red flags that may signal a developmental delay. Some red flags to look for in a three-year-old include difficulty using stairs, inability to form three-word sentences, and lack of pretend play.

Alright, now let’s move on to the milestones of a four-year-old! By this age, the child has achieved several more gross motor milestones, which include hopping on one foot and galloping. Fine motor skills are more advanced, and now the child can hold a pencil properly, draw squares and “X” shapes, write letters, and tie a knot.

A four-year-old has the cognitive skills required to brush their teeth, wash their hands independently, and use a fork. They now know their colors and can count to four. They can also understand analogies, such as, banana is to fruit as broccoli is to vegetable. Social-emotional development now means that the four-year-old has a favorite friend and enjoys group play. Additionally, they are now able to label emotions and are aware of the concept of deception, so they might lie to avoid getting in trouble. Newly acquired language skills include the ability to follow three-step directions and tell stories. A four-year-old uses a vocabulary of 300 to 1000 words, and to a stranger, their speech should be 100% intelligible.