Breastfeeding in the treatment of children with phenylketonuria

Abstract

ResumoObjetivo: Avaliar o efeito do leite materno como fonte de fenilalanina (phe) nos níveis sangüíneos desse aminoácido e no crescimento de fenilcetonúricos. Métodos:Foram estudados 35 fenilcetonúricos que mantiveram leite materno, e os resultados foram comparados com os de 35 lactentes que usaram fórmula láctea comercial. Os grupos foram pareados por sexo e por idade à suspensão do aleitamento materno. Os dados foram analisados até a suspensão do leite materno ou durante 12 meses de acompanhamento. O grupo amamentado recebeu "fórmula especial" isenta em phe, em mamadeira a cada 3 horas, e leite materno em livre demanda nos intervalos. Os níveis sangüíneos de phe, coletados semanalmente até 6 meses e quinzenalmente até 1 ano de idade, foram analisados durante a amamentação. Foram comparados o tempo necessário para adequação dos níveis sangüíneos de phe, após o início do tratamento, utilizando o teste de Wilcoxon e os dados antropométricos, pelo teste t de Student pareado, utilizando o escore z. As dosagens de phe foram analisadas durante a amamentação.Resultados: O tempo mediano para adequação dos níveis de phe no sangue foi de 8 dias para o grupo amamentado e de 7 dias para o grupo controle. As dosagens de phe estavam adequadas em 87% das vezes para o grupo amamentado e em 74,4% para o grupo controle. Na avaliação antropométrica, a maioria das crianças, de ambos os grupos, apresentou escore z > -2. Conclusão:A manutenção do aleitamento materno, durante o tratamento, mostrou-se adequada no controle metabólico e no crescimento das crianças fenilcetonúricas. J Pediatr (Rio J). 2007;83(5):447-452:Aleitamento materno, fenilcetonúria, fenilalanina. AbstractObjective: To evaluate the effect of breastmilk as a source of phenylalanine (phe) on levels of this amino acid and on growth in phenylketonuric infants. Methods:The study recruited 35 breastfed phenylketonuric infants and compared their results with those of 35 infants fed on commercial, milk-based formula. The groups were paired for sex and age at weaning from breastfeeding. Data were analyzed up until cessation of breastmilk or for 12 months' follow-up. The breastfed group were given a "special formula" free of phe, by bottle every 3 hours, and breastmilk at will during the intervals. Levels of phe in the blood, collected weekly up to 6 months and fortnightly up to 1 year de age, were analyzed while breastfeeding continued. The two groups were compared in terms of the time taken for the levels of phe in blood to return to normal after treatment was started, using the Wilcoxon test. Anthropometric data were compared with Student's t paired test in the form of z scores. The phe assays were analyzed throughout breastfeeding. Results:The median time taken for phe levels to return to normal was 8 days for the breastfed group and 7 days for the control group. The phe assay results were normal in 87% of tests for the breastfed group and in 74.4% for the control group. The majority of children in both groups exhibited a z score > -2 on anthropometric examination. Conc...

Breastfeeding Infants with Phenylketonuria in the United States and Canada

“…Almost 70% of mothers (n = 48) met the American Academy of Pediatrics 29 31 In this sample, mothers' with infants who have PKU from the United States and Canada on average breastfed longer than mothers with infants who have PKU from other countries in Europe, Asia, and South America reported by other investigators. 3,10,11,[15][16][17] Those studies consistently reported that the majority of mothers who were breastfeeding infants with PKU did not persist as long as mothers' breastfeeding healthy infants without PKU. Given that statistics for the incidence and duration of breastfeeding infants with PKU from countries outside North America are at least a decade old, current data might reveal more similar rates.…”

“…Consequently, comparison of Phe levels between breastfed and formula-fed infants with PKU was not conducted. Previous studies 2,3,[8][9][10][11]18 have consistently reported that breastmilk supplemented with Phe-free medical beverage is an acceptable dietary treatment for infants with PKU as Phe levels could be maintained within the desired range.…”

“…Although based on relatively small samples of fewer than 50 participants due to PKU's rarity, study results comparing infants with PKU fed breastmilk and supplemented with Phe-free medical beverage versus those exclusively formula fed consistently have reported that breastmilk supplemented with Phe-free medical beverage was an acceptable dietary treatment for infants with PKU as Phe levels could be maintained within the desired range. 2,3,[8][9][10][11] Among women with a child with PKU, there are no large-scale studies reporting the variables related to breastfeeding duration with duration taken as a measure of ''breastfeeding success.'' Nonetheless, studies of overall prevalence of breastfeeding have found the following variables to be linked to duration: older maternal age, white, married status, greater social support, and normal vaginal delivery improve duration, whereas infant health problems shorten duration.…”

“…[12][13][14] Although the practice of breastfeeding infants with PKU has been discussed in the literature, there is limited research describing patterns of breastfeeding in mothers of infants with PKU. 2,3,[9][10][11][15][16][17][18] It is notable that there is no published research identifying factors associated with breastfeeding duration within this unique population of breastfeeding mothers or to support clinical guidelines that specifically address the unique challenges of mothers breastfeeding infants with PKU. Therefore, the purpose of this analysis was to describe the prevalence and duration of breastfeeding among mothers of infants with PKU living in the United States and Canada and to identify factors that affected the duration and success of breastfeeding in this unique population.…”

Acompanhamento do aleitamento materno no tratamento de crianças com fenilcetonúria

“…Traditionally, in the treatment of PKU, breastfeeding (BF) is suspended and the phenylalanine needed is provided through commercial milk-based formula, which amino-acid concentration is known. The amount of formula is determined by blood phenylalanine levels and varies according to the tolerance of each individual to the intake of this amino-acid (5)(6)(7) . The suspension of BF would be necessary because of the difficulty to quantify the intake of phenylalanine during BF, which could cause a wide variation in blood levels and/or keep its concentration at levels above those recommended, incompatible with proper treatment (8)(9)(10) to prevent sequelae.…”