Early feeding practices in infants with phenylketonuria across Europe

Abstract

BackgroundIn infants with phenylketonuria (PKU), dietary management is based on lowering and titrating phenylalanine (Phe) intake from breast milk or standard infant formula in combination with a Phe-free infant formula in order to maintain blood Phe levels within target range. Professionals use different methods to feed infants with PKU and our survey aimed to document practices across Europe.MethodsWe sent a cross sectional, survey monkey® questionnaire to European health professionals working in IMD. It contained 31 open and multiple-choice questions. The results were analysed according to different geographical regions.ResultsNinety-five centres from 21 countries responded. Over 60% of centres commenced diet in infants by age 10 days, with 58% of centres implementing newborn screening by day 3 post birth. At diagnosis, infant hospital admission occurred in 61% of metabolic centres, mainly in Eastern, Western and Southern Europe. Breastfeeding fell sharply following diagnosis with only 30% of women still breast feeding at 6 months.53% of centres gave pre-measured Phe-free infant formula before each breast feed and 23% alternated breast feeds with Phe-free infant formula. With standard infant formula feeds, measured amounts were followed by Phe-free infant formula to satiety in 37% of centres (n = 35/95), whereas 44% (n = 42/95) advised mixing both formulas together. Weaning commenced between 17 and 26 weeks in 85% centres, ≥26 weeks in 12% and < 17 weeks in 3%.DiscussionThis is the largest European survey completed on PKU infant feeding practices. It is evident that practices varied widely across Europe, and the practicalities of infant feeding in PKU received little focus in the PKU European Guidelines (2017). There are few reports comparing different feeding techniques with blood Phe control, Phe fluctuations and growth. Controlled prospective studies are necessary to assess how different infant feeding practices may influence longer term feeding development.

PKU dietary handbook to accompany PKU guidelines

“…of a phenylalanine-free infant formula before each breast feed. This reduces the infant's appetite and hence suckling, thus lowering the amount of breast milk taken and thereby lowering phenylalanine intake [22]. Infants still feed on demand, varying the number of feeds from day to day, but the phenylalanine-free infant formula should always be given first.…”

“…Alternatively, the calculated volume of normal infant formula and phenylalanine-free infant protein substitute can be mixed. This is the most popular method in Europe [22]. A disadvantage of mixing the source of phenylalanine (standard infant formula) with phenylalanine-free infant formula is that the taste may be rejected when the amount of standard infant formula is reduced or removed.…”

Nuclear Magnetic Resonance Metabolomics Reveals Qualitative and Quantitative Differences in the Composition of Human Breast Milk and Milk Formulas

“…According to the European guidelines, the level of phenylalanine in the blood of infants with phenylketonuria should be maintained between 120 and 360 µmol/L. For this reason, the phenylalanine intake is decreased and titrated through combination of breastfeeding or feeding with standard FM with phenylalanine-free infant formula [27]. Therefore, information about the presence of phenylalanine on the label of the first infant formula of brand D seems to be insufficient.…”

¿Qué aspectos considerar al iniciar el tratamiento nutricional para Fenilcetonuria?

“…23 Existen diferentes métodos para administrar la leche materna en los pacientes con PKU: 1) proporcionar una cantidad calculada de fórmula médica sin PHE seguida de lactancia materna a libre demanda, 2) extraer leche materna y proporcionar una cantidad calculada seguida de fórmula médica libre de PHE a libre demanda y 3) alternar las tomas al pecho o leche materna extraída y alimentación con fórmula médica libre de PHE. 24 Es necesario valorar con los padres del paciente la técnica más adecuada para lograr el óptimo control de la PHE en base a las costumbres, hábitos del paciente y su familia. En el caso de un lactante a quien no sea posible ofrecerle lactancia materna, se recomienda como fuente de proteína intacta fórmula infantil de inicio, la cual puede administrarse antes o después de la fórmula médica sin PHE o bien pueden mezclarse en un una misma toma.…”