Nutritional Intervention With Families Of Low-Birth-Weight Infants

Nutrition Research Newsletter, March, 2000

Poor health and nutrition has been implicated in the origin of developmental delays seen in low-birth-weight infants or poorly growing children. Nutrition interventions have shown positive results in the growth of low-birth-weight infants. Good nutrition may compensate for the negative effects of some socioeconomic factors. Preterm infants who are able to grow well during the first year of life have demonstrated improved developmental outcomes. An intervention was recently designed to provide nutritional guidance and support for families' decisions for feeding and nutritional information. This intervention was conducted on a randomized group of low-birth-weight infants, and focused on the effects of nutritional guidance and support in the first year of life to determine if nutritional status, growth rates, and general health could be improved. The study also examined the effects of the intervention on maternal stress.

Families were recruited from a Midwest children's hospital neonatal intensive care unit (NICU). Twenty-nine preterm infants, born at [is less than] 1750 g, were included in the study. There were 11 families and 14 infants in the intervention group, and 14 families with 15 infants in the control group. Families were randomly assigned into either an intervention group or a control group. The total study population consisted of 66% very-low-birth-weight infants ([is less than] 1500 g at birth), 37% of infants with a birth weight [is less than] 1000 g, and sixteen out of the 29 infants were born at 30 weeks gestation or earlier. The infants spent an average of almost nine weeks in the hospital after birth. Twin births were 41% of the sample and were evenly distributed between groups. The most common medical complications after birth were sepsis, jaundice, feeding difficulties of prematurity, apnea, and respiratory distress. Mothers in both groups completed the parent distress section of the short form of the Parenting Stress Index (PSI) at entry into the study and completed the entire form at the end of the intervention period. The instrument was developed to measure adjustment to the parenting role and was broken into three subsets: examining personal distress, parent-child interaction, and a difficult child section. All of the families in the intervention group and 60% of the families in the control group returned the PSI at one year of adjusted age.

At discharge from the hospital, the families received basic nutritional guidance for the immediate post-discharge period, including a formula prescription and recommended daily intake. Infants in both groups were evaluated for developmental progress, growth, and dietary intake at four months, nine months chronological, and 12 months adjusted age. In addition, the intervention group received a monthly phone call from the main researcher to discuss current intake and nutritional concerns with the parent, record any growth measurements, and review recent health information. The nutritional guidance provided was in accordance with the recommendations from the American Academy of Pediatrics. Growth goals were designed to promote catch-up growth and caloric intake goals were set between 100 and 150 kcal/kg/day to meet the Recommended Daily Allowance (RDA) for infants and to allow additional calories for catch-up growth. All of the families expressed at least one nutrition-related concern during the monthly phone calls, and recommendations were made to three families to increase caloric intake.

There are indications that a telephone-based intervention can affect parental expectations and growth in length in preterm, low-birth-weight infants. At 12 months adjusted age, 66% of the infants were developing normally, 10.3% had questionable development, and 24% had abnormal development. The mean total PSI score, the personal distress score, and difficult child score were comparable with the general population. However, the mean score of the parental expectation area indicated that the control parents were disappointed in their children, and the parents of the intervention group were more comfortable with their expectations of their child. This demonstrates that the intervention contributed to a positive establishment of the parent-child bond, whereas the higher score in the control group suggested poor attachment.

There was a trend toward decreased sickness in the smallest birth-weight infants (average 859 g) in the intervention group. Even a small reduction in the rate of repeated illness may have much larger effects when viewed in terms of the cost of medical care and the family's quality of life.

A significant finding of this study was that the mean intake of the infants, both intervention and control groups, at four months actual age was higher than the RDA for infants from birth to six months. This is strong evidence that preterm infants have higher energy needs. This is particularly important because not all preterm infants have the stamina or oral motor coordination to take in the volume required for a higher caloric intake, therefore requiring higher caloric density formulas.