Child development and milestones

Growth charts and developmental milestones are among the most important tools of pediatric screening and monitoring. Growth charts are used to assess height and weight for age, while developmental milestones define the physical, intellectual, and behavioral skills a child with normal development is expected to have acquired by a certain age. Child growth and development are assessed during routine well-child visits at regular intervals. Children whose growth and weight are far below or above average and those who do not meet the developmental milestones for their age group should be evaluated for underlying diseases and receive treatment accordingly. Failure to thrive (FTT) in infants is a condition in which an infant's growth and weight-gain are far below average, the most common cause of which is inappropriate feeding practices. Global developmental delay is defined as the significant developmental failure in two or more domains in children under 5 years of age. The regression of previously achieved milestones may also be a sign of global developmental delay. The persistence of primitive reflexes indicates impaired brain development.

• Primitive reflexes are reflexes that are normally present during infancy and disappear with the development of inhibitory pathways to the subcortical motor areas (usually within the 1^st year of life)
• Primitive reflexes persistence
  • In children; : indicates impaired brain development
  • In adults; : suggests frontal lobe lesions; (frontal release signs)

Plantar grasp and plantar reflex are two different types of primitive reflexes!

References:^{[3][4][5][6][7][8][9]}

Developmental milestones in infancy ^[10][11][12]

Developmental milestones in childhood ^[10][11]

Chronologic age must be adjusted for gestational age for premature infants below 2 years old!

The definition of developmental delay varies depending on the state but as a general rule, developmental delay should be suspected when the child's age is > 25% of the mean age at which a particular milestone is attained or > 1.5 standard deviations on a standardized developmental screening test.

Twins, like all other children, develop at different speeds and each twin should be evaluated separately for any delays in obtaining milestones.

References:^{[13][14][15][16]}

Growth charts are used to calculate a child's growth percentile by plotting the child's weight and height/length on standardized graphs. Height is usually measured standing up, whereas length is measured while the child is lying down.

• Normal weight-for-age velocity
  • Term neonates lose up to 7% of their birth weight in the first few days after delivery and normally regain it within 2 weeks.
  • Birth weight should double by 4 months, triple by 1 year and quadruple by 2 years of age.
• Normal height/length-for-age velocity
  • An infant's height/length increases by approx. 30% within the first 6 months and by approx. 50% within the first year.
  • Midparental height (target height):
    • ♀ height = [mother's height in cm + (father's height in cm - 13)]/2
    • ♂ height = [father's height in cm + (mother's height in cm + 13)]/2
  • From birth to 6 months: 2.5 cm (1 in) per month
  • From 6 months to 1 year: 1.3 cm (0.5 in) per month
• Weight-for-height/length
  • Useful in detecting malnutrition in children < 5 years of age
  • Height/length at 1 year of age should be ∼ 50% more than the birth height/length.
• Head circumference-for-age: used for microcephaly and macrocephaly screening, especially during the first 3 years of life
  • In a healthy infant, head circumference increases by
    • 5 cm during first 3 months.
    • 4 cm between 3–6 months.
    • 2 cm between 6–9 months.
    • 1 cm between 9–12 months.
  • Microcephaly
    • A head circumference that is > 2 standard deviations below the mean size for a given age and sex (usually < 3^rdpercentile)
    • Seen in chromosomal trisomies, fetal alcohol syndrome, congenital TORCH infections, cranial anatomic abnormalities, neural tube defects
  • Macrocephaly
    • A head circumference that is ≥ 2 standard deviations above the mean size for a given age and sex (usually ≥ 97^thpercentile)
    • Seen in hydrocephalus, neurofibromatosis, tuberous sclerosis, skeletal dysplasia, acromegaly, intracranial hemorrhage, cerebral metabolic diseases (e.g., Tay-Sachs disease, maple syrup urine disease)

According to the Rule of Fives, normal growth rates in children can be approximated by multiples of five: birth–1 year (50–75 cm, 25 cm/year), 1–4 years (75–100 cm, 10 cm/year), 4–8 years (100–125 cm, 5 cm/year), 8–12 years (125–150 cm, 5 cm/year).

References:^[17][18][19]

Definition

• Inadequate growth of a child for their age
• Seen in up to 10% of children in the United States (most < 18 months of age)
• Anthropometric criteria of FTT
  • Weight-for-age: < 5^thpercentile
  • Length-for-age: < 5^thpercentile
  • Body mass index-for-age: < 5^thpercentile
  • Deceleration of weight velocity that crosses 2 major lines on the growth chart

Etiology

• Nonorganic FTT (∼ 90% of cases) ^[20]
  • No underlying disorder
  • Usually associated with:
    • Wrong feeding practices
    • Wrong preparation of formula feeds
    • Child neglect
    • Poor socioeconomic status
    • Intrauterine growth restriction
    • Prematurity and low birth weight
• Organic FTT (∼ 10% of cases) is associated with disorders that:
  • Prevent nutrient intake
    • Cleft palate and/or lip
    • Gastroesophageal reflux disease
  • Prevent nutrient absorption
    • Hypertrophic pyloric stenosis
    • Food intolerance
    • Celiac disease
    • Inflammatory bowel disease
    • Inborn errors of metabolism
  • Cause excessive calorie loss
    • Cystic fibrosis
    • Congenital heart defects (CHDs)
    • Malignancies
    • Other chronic diseases

Clinical features

• Developmental delay
• Failure to gain weight despite adequate feeds
• Recurrent vomiting and diarrhea
• Recurrent infections
• General signs of malnutrition (e.g., lymphadenopathy, edema, organomegaly)

Diagnostics

• History of feeding habits (e.g., number and frequency of feeds, food refusal)
• Laboratory studies
  • Complete blood count and ESR
  • Urinalysis
  • Hepatic and renal function tests
  • Thyroid function tests
  • Immunoglobulin levels assessment: to evaluate for underlying immunodeficiencies (e.g., HIV, tuberculosis)
• Imaging
  • Hand and wrist x-ray
  • Echocardiogram
  • Upper gastrointestinal series with small bowel follow-through

Treatment

• Treatment of the underlying cause
• Counseling parents on appropriate child nutrition
• Formula supplementation for infants and nutritional supplementation for toddlers
• Close follow-up and monitoring of the child's growth

References:^[21][22][23]

• Definition: a preventive health care schedule used for general pediatric health assessment, early disease detection, and prompt management.
• Schedule
  • 3–5 days after birth (in-hospital examination)
  • During the first year: at 1, 2, 4, 6, 9, and 12 months
  • During the second year: at 15, 18, 24, and 30 months
  • Between 2 and 10 years of age: annual visits
• Content of the visit
  • Physical examination
  • Charting of growth and developmental milestones
  • Evaluation of resolution of primitive reflexes (in infants)
  • Physical examination at a well-child examination includes:
    • Blood pressure measurement: routinely screened after 3 years of age at each well-child examination
    • Abdomen: for palpable masses (e.g., Wilm tumor, neuroblastoma)
    • Heart: for new murmurs, rate/rhythm disturbances
    • Spine: once the child is able to stand; assess for scoliosis
    • Evaluation for developmental dysplasia of the hip, tibial torsion, femoral torsion, metatarsus adductus
    • Genital exam: for testicular descent, inguinal hernias, congenital hydrocele
  • Screening for visual development and acuity, which includes:
    • Ocular motility and visual acuity assessment (or photoscreening)
    • Physiologic red reflex evaluation; (in newborns): its absence or leukocoria should prompt further workup (see also differential diagnosis of leukocoria)
    • Strabismus and amblyopia screening: Strabismus is a normal finding in children < 3 months of age.
  • Screening for hearing loss in children ^[24][25]
    • Recommended for newborns and then at ages 4, 5, 6, 8, and 10 years
    • Recommended at other ages if there are ≥ 1 risk factors for hearing loss:
      • Family history of childhood hearing loss
      • TORCH infections
      • History of meningitis/head trauma
      • Recurrent or persistent otitis media
      • Neonatal intensive care unit (NICU) stay for > 5 days
    • Screening tests include: electric response audiometry, tympanometry, otoacoustic emissions
    • Undetected hearing loss in children:
      • Can cause speech, language, or social delay
      • May be mistaken for a neurodevelopmental or communication disorder
  • Parents or caregivers education on child nutrition and vaccination

Children with behavioral abnormalities should be tested for hearing loss.

References:^{[24][25][26][27][28]}

• Definition: significant delay in ≥ 2 of the major developmental domains; (gross motor, fine motor, language, cognition, and social milestones) in children < 5 years of age
• Prevalence: up to 5% of children in developed countries
• Etiology
  • Chromosomal abnormalities (e.g., trisomy 13, trisomy 18, trisomy 21, Turner syndrome, Klinefelter syndrome)
  • Metabolic disorders (e.g., phenylketonuria, lysosomal storage diseases, maple syrup urine disease)
  • Infections (e.g., TORCH, herpes simplex, meningitis)
  • Intrauterine exposure to toxic substances/drugs (e.g., alcohol, phenytoin, valproate)
  • Birth complications (e.g., preeclampsia, multiparity)
  • Prematurity
  • Untreated neonatal jaundice
  • Undernutrition, neglect
  • Heavy metal poisoning (lead, mercury)
  • Severe head injuries, intracranial bleeds
  • Cerebral palsy (associated with prematurity, SGA, and perinatal asphyxia)
• Clinical features
  • Mild forms may not be detected until preschool age
  • Severe delay in meeting milestones (see tables above) in ≥ 2 of the major developmental domains (gross motor, fine motor, language, cognition, and social milestones) < 5 years of age
  • Commonly associated with behavioral abnormalities (e.g., ADHD, autism spectrum disorders, bipolar disorders)
• Diagnostics
  • Screening for developmental and intelligence quotient
  • Detailed history, physical examination, and assessment of milestones and primitive reflexes
  • MRI of the brain: to identify CNS malformation, intracranial bleeding or hydrocephalus
  • Genetic testing: if chromosomal anomalies are suspected
  • Screening for infections (e.g., TORCH, HIV): in children with failure to thrive, cranial/cerebral malformations or intracranial calcifications
  • Serum and urine analysis and enzyme studies: In infants suspected of having a metabolic disorder
• Treatment
  • Treatment of the underlying cause (when reversible)
  • Early intervention to minimize the severity of disability
  • Multidisciplinary team: neurologists, orthopedics, physical therapists, speech therapists, nutrition
  • Special schooling and occupational therapy

References:^[29][30]

• Definition: a neurodevelopmental disorder that manifests during the developmental period and affects an individual's intellectual abilities (e.g., abstractive thinking, language, memory) and adaptive functioning (e.g., communication, independent living).
• Prevalence: ∼ 1% in the general population ^[31]
• Etiology
  • Congenital
    • Genetic conditions (e.g., fragile X syndrome, trisomy 21, Klinefelter syndrome)
    • Exposure to teratogens in utero (e.g., fetal alcohol syndrome)
    • Congenital hypothyroidism
    • Congenital infections (e.g., toxoplasmosis, rubella)
    • Perinatal hypoxia
    • Perinatal trauma
  • Acquired
    • CNS infections (e.g., viral encephalitis, meningitis)
    • CNS malignancies (e.g., neuroblastoma)
    • Traumatic brain injury
    • Intoxications (e.g., lead, mercury)
    • Iodine deficiency
    • Malnutrition
• Clinical features
  • The following features should be present:
    • Deficits in cognitive functioning such as learning, problem solving, reasoning, abstract thinking, judgment, and planning
    • Impaired adaptive functioning (e.g., inability to maintain personal independence and social responsibility) leading to educational, occupational, communication, and social problems
    • Onset during the developmental period (during childhood or adolescence)
  • Other features include
    • Features of accompanying mental conditions (e.g., apathy and depressed mood in depression, poor attention in ADHD)
    • Features of the causative conditions (e.g., characteristic appearance in trisomy 21, behavioral problems in Lesch-Nyhan syndrome)
• Diagnostics
  • Intelligence quotient (IQ) testing
  • Workup for identification of underlying disease (e.g., genetic testing, neuroimaging)
• Management
  • Nonpharmacological
    • Psychotherapy (e.g., cognitive-behavioral therapy, family-oriented therapy)
    • Occupational therapy
    • Special education programs
    • Speech-language therapy
  • Pharmacological: used to control psychiatric symptoms of accompanying conditions
    • Atypical antipsychotics (e.g., risperidone, aripiprazole, olanzapine) ^[32]
    • Antidepressants (e.g., SSRIs)

References: ^[31][33][34]

• Definition
  • A neurodevelopmental disorder that occurs due to a combination of genetic, epigenetic, and environmental factors and results in difficulties learning and applying specific academic skills
  • Features should be present for more than 6 months despite academic interventions to address these problems.
• Prevalence: 5–15% in the school-age population ^[33]
• Clinical features
  • Inability to acquire age-appropriate academic skills, such as reading (most common), spelling, writing, operations with numbers,or mathematical reasoning
  • General cognitive abilities (e.g., reasoning, abstract thinking) are normal (in contrast to intellectual disability)
• Management
  • Academic support (e.g., individualized learning programs)
  • Regular school psychology consultations
  • Individual or family psychotherapy
  • Extracurricular activities to improve academic and social inclusion

References: ^[33]