Is Developmental Delay a Major Child Health Problem?

Questions about child development commonly arise during the pediatric office visit. Family members may voice specific concerns, or the physician may be the first to suggest that a child is developing slowly. Each health supervision visit should include a brief assessment of developmental milestones. If the family or healthcare provider suspects a delay, however, a more thorough investigation is warranted. The causes of developmental delay are diverse, and systematic thinking through the classes of possible etiologies is needed to identify the cause of a child’s problems. Many cases of developmental delay elude diagnosis, because most children with mild mental retardation have unremarkable prenatal and birth histories, normal laboratory profiles, and normal head imaging results. The likelihood of identifying a specific etiology tends to increase with the degree of developmental delay. Parents almost always ask, “How did this happen?”—a question that you may not always be able to answer.

What Functional Deficits Occur in Developmental Delay?

A child with developmental delay has deficits in one or more of the following functions:

A problem in one area can affect ability in another. For example, the input problem of sensorineural hearing loss can diminish the processing ability to understand the nuance of spoken language, even after the loss is treated. A specific disability can cause deficits in all three functions: Cerebral palsy (Chapter 58), for example, may be associated with the input disorders of strabismus and sensorineural hearing loss; processing problems, including mental retardation and learning disabilities; and output problems of spasticity and contractures.

How Do I Determine the Cause of Developmental Delay?

Once you identify the functional deficits, you can begin to think about causes. Tables 27-1, 27-2, and 27-3 indicate the most common etiologies for input and processing deficits. These lists include general categories of disease and the most common causes of developmental delay.

Table 27-1 Causes of Hearing Loss in Children

Table 27-2 Causes of Visual Loss in Children

Table 27-3 Causes of Mental Retardation in Children

What Questions Should I Ask the Family?

Genetic, prenatal, environmental, and many other factors can contribute to developmental differences. Your history must be as inclusive as possible. Where possible, information from each phase of the child’s life should be recorded so that patterns may be identified. Conduct the interview in language that is easily understood by most families. For example, the question, “Is there anyone related to your son who had a hard time learning to read, or reads with difficulty now?” is much more likely to elicit useful information than the query, “Do you have a family history of dyslexia?” Certain elements of the history are standard in the structured workup of any child with suspected developmental delay. The following questions are by no means comprehensive, but including them in your history should help you screen for the most prevalent developmental disorders on a typical pediatric clerkship.

What Should I Ask about Prenatal Events?

A thorough prenatal history obtained using gentle, open-ended questions will lead you to areas that may require more probing. A brief inquiry into the mother’s prepregnancy health will yield information about collagen vascular disease, diabetes, seizure disorder, and other potentially teratogenic health issues. Queries related to the pregnancy itself require particular care, because the mother of a developmentally delayed child often feels at fault for the child’s problems; she may be exquisitely sensitive to any nuance of blame in the interview. In general, however, parents will talk freely if you listen actively and encourage them to tell their story. You can do so by asking about the clinical details outlined in Table 27-4 and about the quality of the pregnancy experience itself: If the mother has given birth before, was this pregnancy easier or harder than the other(s)? Did the mother have the “flu,” a urinary tract infection, or other illnesses during her pregnancy? Did this baby move around more or less than her other babies? What tests did the doctor do? (You may or may not already have this information). Did the mother need to take any special medications or to rest in bed to prevent premature delivery of the baby? The prenatal history should also include inquiry about prescription drugs, over-the-counter medications, and vitamin supplements taken by the mother at any point during the pregnancy. Table 27-5 lists commonly used medications associated with developmental problems. Questions about alcohol, tobacco, and drug consumption during pregnancy should be carefully posed to avoid the appearance of casting blame. If you frame the inquiry neutrally you are more likely to learn what you need to know: “I ask every parent about drinking and use of substances such as pot, cocaine, and meth during pregnancy. Did you use any? And if so, how much?”

Table 27-4 Pregnancy-Related Historical Factors Associated with Developmental Delay

Table 27-5 Prenatal Medications Associated with Developmental Delay

What Should I Ask about Labor and Delivery?

Ask about length of labor, mode of delivery, any assistive methods such as forceps or vacuum, and any needed resuscitation. A simple way to ask about resuscitation is, “Did [child’s name] need help breathing right after he was born?” You should also ask the mother if she had a fever or was treated for an infection during labor because studies have linked cerebral palsy to maternal reproductive tract infection. Look in the record for Apgar scores and notes about labor and delivery.

What Postnatal Events Should I Document?

Review any health problems identified in the nursery, such as respiratory distress, jaundice, hypoglycemia, anemia, and fever. If the infant underwent head ultrasound or other head imaging in the nursery, obtain the results. Note the recommendations made at discharge, including need for supplemental oxygen, apnea monitoring, and supplemented or nonoral feeding.

What about the Child’s Health History?

History of the child’s general health from birth to the time of the evaluation should identify any head injury, seizures, serious illness, hospitalizations, or surgeries. Medications and allergies should be reviewed. Any hearing or visual loss should be noted, as should results of hearing and vision screens. You should review the child’s appetite, sleep habits, and bladder and bowel function.