Background:
Phenylketonuria (PKU) is known as a genetic disorder that results in severe mental retardation if not identified and treated quickly with a diet low in phenylalanine (Phe). Michigan as well as most other states, initiated PKU screening in the 1960's. About twenty years later, some of the children born to females with PKU, in the U.S. and other countries, presented with myriad cognitive and physical problems (i.e., congenital heart defects, microcephaly, dysmorphic facial features, mental retardation) due to the teratogenic effects of elevated maternal blood phenylalanine on the developing fetus. This is known as the Maternal PKU (MPKU) syndrome that occurs when females with PKU do not adhere to strict dietary treatment. Assessing the health status of women with PKU is needed prior to conception.

Objectives:
To understand the long term implications of NBS program and the impact on strategies and standard of care as they relate to preconception health.

Methods:
The clinical database of PKU patients born between 1965 and 1992 and treated at the Metabolic Medical Management Center was used for this study. The incomplete information on Phe levels limited our ability to compare pregnancy outcomes in diet-controlled PKU versus non-controlled by using the retrospective cohort design. Univariate and bivariate analyses were conducted instead, as permitted by the data available.

Results:
There were 350 PKU cases diagnosed in Michigan between 1965 and 1992. Information was found on 54 women that had 91 pregnancies. Of 91 pregnancies, 37% (34) were to 25 women (46.3% of 54) having classic PKU, 29.7% (27) to women with a mild form (13 women; 24.1% of 54) and 33% (30) to those having Hyperphe (16 women; 29.6% of 54). Less than one third (28; 30.8%) ended in abortions (12 therapeutic and 16 spontaneous) and 63 (69.2%) in live births. Twenty-eight offspring were reported as normal at birth (44.4%) and about one in fourth as having microcephaly. No information was found on more than half.

Conclusion and implications for practice:
As those diagnosed through this program become adults, public health professionals are challenged to include preconception assessment within NBS long-term follow up strategies and standards of care.