Methodical Recommendations
for Students’ Self-work №__.
Theme: Nutritional needs of preterm infants.
Aim: To learn the peculiarities and special nutritional needs of preterm
infants.
Professional necessity of the theme: Prematurely born infants are of highrisk group, they have a greater than average chance of morbidity or mortality. So
they need special care and medical supervising to help them to grow healthy.
Nutrition is one of special and very important aspects of such care. Especially,
because premature babies have immature digestive tract, which isn’t able to digest,
sometimes, even breast milk.
Technique of realization of practical Work
1. To know peculiarities of digestive tract of premature infants
2. To know transitional conditions of neonate period
3. To know peculiarities of physical and neurological examination of a
newborn child
4. To know main rules and techniques of breast and formula feeding of
infants
Programme of student’s self-preparation.
Gestational age,
birth weight
1. First feeding of premature neonates
in dependence on gestational age.
Rules of feeding
Time of first
Volume of
Type of food
feeding
Less than
34 weeks,
less than 2 kg
In 2 – 3 hours
(!)
after delivery
1 feeding
First feeding –
distilled water,
second – 5 % glucose,
others – breast milk*
2-4 ml
Regimen of
feeding
8-9 times
per day
More than
In 2 – 3 hours
7 times
34 weeks,
(!)
Breast milk
5-7 ml
per day
more than 2 kg after delivery
*breast milk can be given only in case if there is no regurgitation after intake of 5
% glucose
2. Requirements of premature infants.
The energy expenditures for maintenance and the energy costs of growth are
the determinants of the caloric requirements of the growing infant. The energy
expenditure for growth includes both the energy value of the new tissue stores and
the energy cost of the tissue synthesis. The estimated "basal" or maintenance
metabolic rate of preterm infants, including an irreducible amount of physical
activity, is lower in the first week after birth than later; and, in a thermoneutral
environment, it is approximately 50 kcal/kg per day by 2 to 3 weeks of age. Each
gram of weight gain, including the stored energy and the energy cost of synthesis,
requires 5 to 6 kcal. Thus a daily weight gain of 15 gm/kg requires a caloric
expenditure of approximately 75 kcal/kg above the 50 kcal/kg maintenance
expenditure (See table 2.).
There are individual variations among infants in activity, their ease of achievement
of basal energy expenditure at ther-moneutrality, and the efficiency of their
nutrient absorption. In practice, intake by the enteral route of approximately 120
kcal/kg per day enables most preterm infants to achieve satisfactory rates of
growth. More calories may be given if growth is unsatisfactory at these intakes.
Newborn infants who are growth retarded frequently require an increased energy
intake for growth because of both higher maintenance needs and higher energy
costs of new tissue synthesis.
Table 2. Requirements of premature infants.
Age
Proteins (g/kg)
Fats (g/kg)
Carbohydrates (g/kg)
Birth – 2 wks:
1-3 days
7 days
10-14 days
2 wks – 1 mo
2 mo
After 2 mo
2-2.5
5.5
12-15
2.5-3.0
3.0-3.5
3.0-3.5
6.0
6.5
6.5
12-15
12-15
12-15
Kcal/kg
30-60
70
100-120
100-120
135-140
130
Caloric Density and Water Requirements
The caloric density of both preterm and term human milk is about 67 kcal/dl at 21
days of lactation. Formulas of this caloric density have been used for feeding
preterm infants. However, more concentrated milks, 81 kcal/dl (24 kcal/oz), are
preferred by many when commercial infant formulas are used. The increased
concentration allows feeding volumes to be smaller, an advantage when gastric
capacity may be limited. The volume given when formulas of this concentration
are fed at the rate of 120 kcal per kilogram per day, 150 ml per kilogram per day,
provides sufficient water for most preterm infants for the excretion of protein
metabolic products and electrolytes derived from the formula. However, if lower
volumes of formula are given, insufficient water may be provided for renal
excretion when relatively constant extrarenal losses occur.
3. Human milk and preterm infants.
Preterm infants fed with their mother's milk have a more rapid rate of growth in
weight, length, and head circumference, as well as a shorter time to regain birth
weight, than those fed milk from the mothers of term infants. Pooled human milk
from mothers of term infants does not meet all nutritional requirements of preterm
infants and results in a slower rate of growth than is found with consumption of
milk from mothers of preterm infants or commercial infant formulas. The low
protein concentration of pooled, term human milk is probably the major cause of
the poor growth; metabolic complications include hyponatremia at 4 to 5 weeks,
hypoproteinemia at 8 to 12 weeks, and rickets at 4 to 5 months.
Milk from mothers of preterm infants, especially during the first 2 weeks after
delivery, contains more calories; higher concentrations of fat, protein, and sodium;
but slightly lower concentrations of lactose, calcium, and phosphorus than milk
from mothers of term infants. These differences in composition may be mainly a
result of the lower daily volume of milk produced by the mothers of preterm
compared to mothers of term infants. The higher fat content leads to the higher
caloric density of preterm milk, which may be advantageous for the small infant
with limited gastric capacity. The higher protein content of preterm milk is
sufficient to meet the fetal growth requirement for nitrogen when the milk is
consumed at 180 to 200 ml per kilogram per day.
4. Commercial Formulas for Preterm Infants
Many results of studies on nutrient, electrolyte, mineral, and vitamin needs
and tolerances of preterm infants, which were discussed earlier in this chapter,
have been applied to the development of formulas specifically designed to meet the
needs of small preterm infants. The common features of these commercial infant
formulas are the use of whey-predominant proteins, carbohydrate mixtures of
lactose and glucose polymers, and fat mixtures containing combinations of MCT
and relatively unsaturated long-chain triglycerides. The formulas differ in content
of sodium, calcium, phosphorus, vitamins, and minerals. Each of the special
formulas has been shown to be associated with adequate growth and metabolic
stability.
PreHIPP
PreNAN
5.Methods of Enteral Feeding
The method of enteral feeding chosen for each infant should be based on
gestational age, birth weight, clinical state, and experience of nursing personnel.
Coordination of sucking, swallowing, and respiration appears at approximately 32
to 34 weeks' gestation. Preterm infants of this gestational age who are alert and
vigorous may be fed by nipple. Infants who are less mature, are weak, or are
critically ill will require alternate modes of feeding by vein or tube to avoid the risk
of aspiration and to conserve energy. Gastric feeding of boluses of milk can lead to
disturbances of respiratory function in infants with respiratory problems; thus, in
some infants, continuous transpyloric feedings by nasal or oral tubes have become
popular. Clinical results of this feeding mode have been excellent in many
nurseries, but there have been some criticisms that bypassing the stomach and
duodenum by ajejunal tube may cause inefficient utilization of the nutrients in the
formula. Continuous gastric feedings may be tolerated by many small infants better
than bolus gastric feedings, and they are satisfactory if gastric emptying is not
limiting in the infant. Bolus feedings into the stomach via gavage tube or by
nipple, every 2 to 3 hours, is the goal after the preterm infant shows a clearing of
the respiratory distress and gastric emptying is not a problem. Whatever the mode
of feeding, the formula volume should be advanced slowly - over at least 10 to 14
days in infants who weigh less than 1,000 gm and 6 to 8 days in infants who weigh
more than 1,500 gm.
6. Parenteral Nutrition
Parenteral administration of glucose, fat, and amino acids is frequently an essential
part of the nutritional care of preterm infants, particularly those who weigh less
than 1,500 gm. The high incidence of respiratory problems, limited gastric
capacity, and intestinal hypomotility in small preterm infants dictates the need to
advance the volume of enteral feedings slowly. The availability of parenteral
nutrition components enables the supplementation of the slowly enlarging enteral
feedings so the total daily intake by both routes meets the infant's nutrition needs.
When required, full nutrition requirements can be met for considerable periods by
the parenteral route alone.
References
1. Committee on Nutrition: Nutritional needs of low-birth-weight infants. PEDIATRICS, 60:519,
1977.
2. Ziegler, E.E., Biga, R.L., and Fomon, S.J.: Nutritional requirements of the premature infant. In
Suskind, R.M., ed.: Textbook of Pediatric Nutrition. New York: Raven Press, pp. 29-39,
Textbook of Pediatric Nutrition. New York: Raven Press, pp. 29-39, 1981.
3. Reichman, B., Chessex, P., Putet, G., Verellen, G., Smith, J.M., Heim, T., and Swyer, P.R.:
Diet, fat accretion, and growth in premature infants. New Engl. J. Med., 305:1495, 1981.
4. Gordon, H.H., Levine, S.Z., and McNamara, H.: Feeding of premature infants. A comparison
of human and cow's milk. Amer. J. Dis. Child., 73:442, 1947.
5. Gaull, G.E., Rassin, D.K., Raiha, N.C.R., and Heinonen, K.: Milk protein quantity and quality
in low-birth-weight infants. III. Effects on sulfur ammo acids in plasma and urine. J. Pediat,
90:348, 1977.
6. Raiha, N.C.R., Heinonen, K., Rassin, D.K., and Gaull, G.E.: Milk protein quantity and quality
of low-birthweight infants. I. Metabolic responses and effects on growth. PEDIATRICS, 57:659,
1976.
7. Fomon, S.J., Ziegler, E.E., and Vazquez, H.D.: Human milk and the small premature infant.
Amer. J. Dis. Child. 131:463, 1977.