Chapter 8 Growth and Nutrition PDF

Examination and Findings 120 CHAPTER 8 Growth and Nutrition FIG. 8.6 Place the measuring tape around the largest circumference of the infant’s head, across the occiput and the forehead. Chest Circumference Although the chest circumference is not used routinely, it is a useful measurement for compari...

Examination and Findings 120 CHAPTER 8 Growth and Nutrition FIG. 8.6 Place the measuring tape around the largest circumference of the infant’s head, across the occiput and the forehead. Chest Circumference Although the chest circumference is not used routinely, it is a useful measurement for comparison with the head circumference when a problem is suspected with either the head size or chest size. Wrap the measuring tape around the infant’s chest at the nipple line firmly but not tight enough to cause an indentation of the skin (Fig. 8.7). Read the chest circumference measurement midway between inspiration and expiration to the nearest 0.5 cm or 0.25 inch. The newborn’s head circumference may equal or exceed the chest circumference by 2 cm (0.75 inches) until 5 months of age. Between the ages of 5 months and 2 years, the infant’s chest circumference and head circumference are close to the same size. If an infant’s head circumference is smaller than the chest circumference, consider evaluating the infant for microcephaly. After 2 years of age, the chest circumference exceeds the head circumference because the chest grows faster than the head. Gestational Age Gestational age is an indicator of a newborn’s maturity. One method of determining gestational age is to calculate the number of completed weeks between the first day of the mother’s last menstrual period and the date of birth. An estimate of gestational age is used to evaluate an infant’s developmental progress. It is also used to identify preterm newborns of appropriate size and term newborns who are small for gestational age. The Ballard Gestational Age Assessment Tool evaluates six physical and six neuromuscular newborn characteristics within 36 hours of birth to establish or confirm the newborn’s gestational age (www.medcalc.com/ballard.html). The assessment is accurate within 2 weeks of the assigned gestational age. Scores are more accurate for extremely preterm newborns when the assessment occurs within 12 hours of birth. The gestational ages of 37 through 41 weeks are considered term and are associated with the best health outcomes. Infants born before 37 weeks of gestation are preterm, and infants born after 41 completed weeks of gestation are postterm. The incidence of premature birth FIG. 8.7 Measurement of infant chest circumference with the measuring tape at the level of the nipple line. in the United States reached a peak in 2006 when 12.8% of all infants were born at gestational age less than 37 weeks. Since that time, the rate of premature birth has continued to decrease slowly to just below 10% (Hamilton et al., 2015) Size for Gestational Age. A newborn’s fetal growth pattern and size for gestational age can be determined once gestational age is assigned. An intrauterine growth curve is used to plot the newborn’s birth weight, length, and head circumference. The Fenton Growth Chart is recommended for tracking premature growth until 50 weeks postmenstrual age (https://live-­ucalgary.ucalgary.ca/reso urce/preterm-­growth-­chart/preterm-­growth-­chart). The infant is classified as small, appropriate, or large for gestational age by percentile curve placement for weeks of gestation (Fig. 8.8). The classification system is as follows: Appropriate for gestational age: 10th to 90th weight percentile Small for gestational age: less than 10th weight percentile Large for gestational age: greater than 90th weight percentile Infants who are small or large for gestational age have an increased risk for morbidity and mortality. Small for gestational age infants who are full term have an increased risk for respiratory distress, hypoglycemia, and other health problems. In 2014, 8.0% of infants were born at low birth weight (