The success of the nationwide neonatal phenylketonuria (PKU) screening programs
implemented in the early 1960's created an unexpected problem as women with PKU reached
childbearing age. Retrospective surveys have revealed that maternal blood phenylalanine
(phe) levels > 20 mg/dl during pregnancy are associated with a high rate of mental
retardation, microcephaly, congenital heart defects, and intrauterine growth retardation
among non-PKU offspring, of women with Hyperphenylalaninemia (HPA). It is estimated
that at least 3,000 HPA women, between the ages of 16 and 26 are at risk for pregnancy in
the United States and Canada.
To study this problem, the National Institute of Child Health and Human Development,
NIH, launched a collaborative effort involving fifty states, the District of Columbia, and all
of the provinces of Canada. In 1992, Germany, Austria and Switzerland have joined the
Study. The Maternal PKU Collaborative Study (MPKUCS) is a prospective, longitudinal,
observational investigation designed to evaluate the efficacy of a phenylalanine-restricted diet
in reducing the morbidity associated with Maternal Hyperphenylalaninemia (HPA).
The enrollment of HPA subjects commenced on November l, 1984, and ended on June
30, 1995. Women of childbearing age, whose blood phenylalanine (Phe) concentrations
while on unrestricted diets are > 4 mg/dl, were invited to participate in the Study. Women
> 14 years of age were encouraged to enroll in the MPKUCS independent of plans for
pregnancy, in order to identify and counsel them about the importance of initiating dietary
therapy prior to conception.
The plan of treatment for women desiring pregnancy involved the initiation of diet prior
to conception, the provision of adequate nutrition during pregnancy, maintaining blood phe
between 2-6 mg/dL, and dietary supplementation with tyrosine and other micronutrients, as
medically indicated.
For purposes of the Study's protocol, monitoring during pregnancy includes routine
prenatal examinations, laboratory tests, nutritional evaluations, and ultrasound for the
determination of gestational age and intrauterine growth. Offspring will be followed to
school age to assess physical, neurological, cognitive, behavioral and psychosocial
development. Data are also being collected on office-matched, and on familial control
subjects, on pregnant obligate heterozygotes for PKU, and on pregnant mates of HPA males.
Contributing Centers
Question or Comments? Please send e-mail to rkoch@almaak.usc.edu
Pages last updated 5/28/97