Unit of Metabolic Diseases and Clinical Dietetics - DIMEC, "Alma Mater" University, Bologna, Italy.
Unit of Pediatrics - DIMEC, "Alma Mater" University, Bologna, Italy.
Nutr Metab Cardiovasc Dis. 2020 Jun 9;30(6):977-983. doi: 10.1016/j.numecd.2020.02.003. Epub 2020 Feb 20.
Phenylketonuria (PKU)-affected women may become pregnant, and dietary phenylalanine (Phe) intake must be adjusted according to Phe tolerance. We report our experience with maternal PKU in relation to genotype PKU heterogeneity.
A total of 10 pregnancies in 7 PKU women (7 different genotypes) were followed up as part of personalized care. Phe tolerance during preconception and pregnancy was assessed by strict dietary control and weekly Phe measurement (blood spots) in relation to genotype. Most women had stopped PKU diet during childhood or adolescence and six pregnancies were unplanned; a phenylalanine-restricted diet was reinstituted soon after conception. Women were classified according to their Phe levels at birth screening and genotype. Phe tolerance increased systematically in the course of pregnancy in all cases, but the increase was different in subjects with classic PKU (cPKU) when compared with cases with mild hyperphenylalaninemia (mHPA), both on average (+297 mg/day in cPKU vs. 597 in mHPA; P = 0.017) and as percentage (+107% in cPKU vs. +17% in mHPA). Notably, Phe tolerance also varied in the same women in the course of different pregnancies, when body weight gain was also different. Two newborns from the same cPKU mother (unplanned pregnancies on free diet) were affected by congenital alterations.
Several factors influence metabolic phenotype in maternal PKU, to an unpredictable extent even in the same woman. The number of maternal PKU cases is growing in dedicated Nutrition Units, and the burden associated with careful management of this condition for the health care system should be adequately considered.
苯丙酮尿症（PKU）患者可能会怀孕，并且必须根据苯丙氨酸（Phe）耐受情况调整饮食中的 Phe 摄入量。我们报告了与 PKU 基因型异质性相关的母体 PKU 经验。
在个性化护理中，共随访了 7 名 PKU 女性（7 种不同基因型）的 10 例妊娠。在受孕前和妊娠期间，通过严格的饮食控制和每周进行与基因型相关的血斑 Phe 测量来评估 Phe 耐受性。大多数女性在儿童期或青春期已停止 PKU 饮食，并且有 6 例妊娠是意外的；妊娠后立即重新开始限制 Phe 的饮食。根据出生筛查时的 Phe 水平和基因型对女性进行分类。在所有情况下，Phe 耐受性在妊娠过程中均系统增加，但经典 PKU（cPKU）患者的增加与轻度高苯丙氨酸血症（mHPA）患者不同，平均增加（cPKU 增加 297mg/d，mHPA 增加 597mg/d；P=0.017）和百分比（cPKU 增加 107%，mHPA 增加 17%）。值得注意的是，在同一女性的不同妊娠过程中，Phe 耐受性也有所不同，体重增加也有所不同。同一位 cPKU 母亲的两个新生儿（自由饮食的意外妊娠）患有先天性改变。
多种因素影响母体 PKU 的代谢表型，即使在同一女性中，其影响程度也难以预测。专门的营养单位中母体 PKU 的病例数量正在增加，并且应充分考虑为医疗保健系统管理这种情况带来的负担。
