Literature review for - Flourish Paediatrics

The PKU handbook includes the following information on early infant feeding:
It is possible to breastfeed infants with PKU and keep the plasma Phe at a safe level.
Breastmilk contains much less Phe than infant formula. However, breastmilk alone contains
too much Phe for infants with PKU. A Phe-free formula is given by bottle to reduce the
infant’s appetite before breastfeeding. After diagnosis infants may require a diet of solely
Phe-free formula until the high Phe plasma levels drop. Mothers wishing to continue
breastfeeding are recommended to express breastmilk during this period to ensure their milk
supply is maintained. After the first few days, breastfeeds are given after a measured amount
of Phe-free formula. Most babies with PKU need about half the usual amount of breast milk,
but this varies. If an infant is showing signs of hunger, offer more breastfeeds after their Phe
free formula. For the formula fed infant, after the first few days, standard infant formula is
usually given before the Phe-free formula. If an infant is showing signs of hunger offer more
Phe-free formula. The order in which the Phe-free formula is offered may vary from time to
time.
The PKU handbook includes the following information on the introduction of solid foods:
Solids are introduced at four to six months and start with very small amounts of low
phenylalanine foods such as fruit and vegetables. Phenylalanine levels in rice and wheat are
too high. A little milk free margarine can be added to the vegetables for extra energy and to
make a smoother puree. Children with PKU also need plenty of essential fats which come
from vegetable oils such as olive, canola, soya, sunflower, safflower and peanut oils. From
seven to nine months small amounts of food with low phenylalanine content such as stewed
apple, low-protein pasta and low-protein custard are introduced. Finger foods and low protein
bread with milk-free margarine can be offered to encourage infants to chew. Parents learn to
count phenylalanine units in the diet and breastfeeding or infant formula will be decreased
from this age.
A cohort study conducted in South Australia aimed to describe the feeding regime of infants
diagnosed with PKU and assess the efficacy of this method. Of the 27 infants in the cohort
study, 22 of them were receiving breastmilk prior to diagnosis and all 22 recommenced
breastfeeding once phenylalanine levels were below 600 µmol/L. Upon diagnosis infants
were fed phenylalanine-free formula, followed by breastfeeding until satiety. The volume of
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