Preventing maternal phenylketonuria (PKU) syndrome: important factors to achieve good metabolic control throughout pregnancy

Abstract

Background Insufficient metabolic control during pregnancy of mothers with phenylketonuria (PKU) leads to maternal PKU syndrome, a severe embryo-/fetopathy. Since maintaining or reintroducing the strict phenylalanine (Phe) limited diet in adults with PKU is challenging, we evaluated the most important dietary and psychosocial factors to gain and sustain good metabolic control in phenylketonuric women throughout pregnancy by a questionnaire survey with 38 questions concerning therapy feasibility. Among them, the key questions covered 5 essential items of PKU care as follows: General information about maternal PKU, PKU training, diet implementation, individual metabolic care, personal support. In addition, all participating PKU mothers were asked to estimate the quality of their personal metabolic control of the concluded pregnancies. 54 PKU mothers with 81 pregnancies were approached at 12 metabolic centers in Germany and Austria were included. According to metabolic control, pregnancies of PKU women were divided in two groups: group “ideal” (not more than 5% of all blood Phe concentrations during pregnancy > 360 µmol/l; n = 23) and group “suboptimal” (all others; n = 51). Results The demand for support was equally distributed among groups, concerning both amount and content. Personal support by the direct social environment (partner, family and friends) (“suboptimal” 71% vs “ideal” 78%) as well as individual metabolic care by the specialized metabolic center (both groups around 60%) were rated as most important factors. The groups differed significantly with respect to the estimation of the quality of their metabolic situation (p < 0.001). Group “ideal” presented a 100% realistic self-assessment. In contrast, group “suboptimal” overestimated their metabolic control in 53% of the pregnancies. Offspring of group “suboptimal” showed clinical signs of maternal PKU-syndrome in 27%. Conclusion The development of training programs by specialized metabolic centers for females with PKU in child bearing age is crucial, especially since those mothers at risk of giving birth to a child with maternal PKU syndrome are not aware of their suboptimal metabolic control. Such programs should provide specific awareness training for the own metabolic situation and should include partners and families.

Seguimiento bioquímico y dosis de medicamentos de EIM del metabolismo intermedio

“…10,11,32 Por ejemplo, en los pacientes con fenilcetonuria las concentraciones sanguíneas de fenilalanina recomendadas, eran diferentes dependiendo del grupo de edad, actualmente existe evidencia que señala la necesidad e importancia de mantener dichas concentraciones sanguíneas entre 120-360 mol/L para todos los grupos de edad, 34 dados los déficits y problemas neurológicos que los pacientes adolescentes y adultos presentaban, 38 así como para prevenir la fenilcetonuria materna. 39…”

Impact of pregnancy planning and preconceptual dietary training on metabolic control and offspring's outcome in phenylketonuria

“…Furthermore, dietary training programs can improve the awareness of women with PKU in child-bearing age for their own metabolic control as recently demonstrated. 32 The potential influence of the socioeconomic status on achieving metabolic control during pregnancy has been postulated by several authors. 10,11,13,33 We could not confirm a strong impact of socioeconomic status and education; however, we cannot exclude that maternal education might have an indirect impact.…”

Fetal neurosonographic phenotyping of inborn errors of metabolism

“…PKU is characterised by abnormally elevated blood phenylalanine levels. Untreated or poorly controlled maternal PKU can cause fetal microcephaly, congenital heart disease, structural anomalies, and fetal growth restriction 1 . To date, the definition of IEM is further defined as any condition leading to the dysfunction of specific enzymes or disruption of biochemical pathways intrinsic to the pathomechanism 2,3 .…”