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B Rouse

Publications and source records attributed to B Rouse.

27 records · Page 2Linked to original sources
PubMed1993

The North American Collaborative Study of Maternal Phenylketonuria. Status report 1993.

Neonatal screening for phenylketonuria (PKU) has created an unexpected problem as females with PKU are reaching childbearing age. Surveys have revealed that maternal phenylalanine blood concentrations above 1200 mumol/L are associated with microcephaly, mental retardation, congenital heart defects, and intrauterine growth retardation among their offspring. It is estimated that as many as 3000 hyperphenylalaninemic females may be at risk for producing these fetal abnormalities. To examine this problem, the North American Maternal PKU Collaborative Study has been developed to evaluate the efficacy of a phenylalanine-restricted diet in reducing fetal morbidity. Preliminary findings indicate that phenylalanine restriction should begin before conception for females with PKU planning a pregnancy. Dietary control should maintain maternal blood phenylalanine levels between 120 and 360 mumol/L and should provide adequate energy, protein, vitamin, and mineral intake. Pregnant hyperphenylalaninemic females who achieved metabolic control after conception or by the 10th week of pregnancy had a better offspring outcome than anticipated.

Adolescent↗
PubMed1992

Maternal phenylketonuria collaborative study, obstetric aspects and outcome: the first 6 years.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of a phenylalanine-restricted diet in reducing fetal morbidity associated with maternal hyperphenylalaninemia in women of childbearing age with blood phenylalanine levels greater than 240 mumol/L (greater than 4 mg/dl) on an unrestricted diet. STUDY DESIGN: Two hundred thirteen pregnant women with hyperphenylalaninemia that resulted in 134 live births have been enrolled in the study. Outcome measures were subject to the chi 2 test, Fisher exact test, analysis of variance, t test, or Wilcoxon nonparametric test for analysis. RESULTS: Optimal fetal outcome appeared to occur when blood phenylalanine levels less than 600 mumol/L (less than 10 mg/dl) were achieved by 8 to 10 weeks' gestation and maintained throughout pregnancy (trimester averages of less than or equal to 360 mumol/L (less than or equal to 6 mg/dl). Initiation of dietary therapy during the third trimester of pregnancy appears to have little beneficial effect on the fetus. CONCLUSIONS: Preconceptual counseling and early entrance into a prenatal care program is essential in achieving optimal fetal outcome in women with hyperphenylalaninemia.

Congenital Abnormalities↗
PubMed1990

A preliminary report of the collaborative study of maternal phenylketonuria in the United States and Canada.

The Maternal Phenylketonuria Collaborative Study (MPKUCS), encompassing all the United States and provinces of Canada, is a prospective, longitudinal investigation designed to ascertain the efficacy of phenylalanine-restricted therapy in protecting the fetus from high maternal phenylalanine concentrations in women with hyperphenylalaninaemia. Preliminary findings are reported for 147 pregnancies for whom the recommended therapeutic range of blood phenylalanine was 120-360 mumols/L. Sixty-three pregnancies had complete data for analysis. Dietary control was attempted prior to conception in 10 out of 63 women. Significant negative correlations were noted in length, weight and head circumference and blood phenylalanine concentrations during pregnancy. Average reported phenylalanine levels by trimester for 63 hyperphenylalaninaemic pregnancies resulting in live births revealed that no group requiring treatment achieved levels below 360 mumols/L until the third trimester. Median birth measurement percentiles revealed that all groups studied generally had smaller head size compared with birth length and weight. Those started on diet after the first trimester achieved a head circumference below the 10th percentile. The implication of small head circumference for subsequent intellectual development is unclear at this time. Furthermore, the study must evaluate more offspring of women having optimal preconception and pregnancy restriction of phenylalanine.

Canada↗
PubMed1990

Neuropsychology of early-treated phenylketonuria: specific executive function deficits.

This study explored the hypothesis that children with early-treated phenylketonuria (PKU) are selectively impaired on executive function measures, even when still on diet. The rationale for this hypothesis is that even mild elevations in phenylalanine (Phe) can lead to lower central levels of biogenic amines, including dopamine (DA). We hypothesize that this mild DA depletion causes subtle prefrontal dysfunction, which in turn affects executive functions such as set maintenance, planning, and organized search. 11 preschool early-treated PKU children (M age = 4.64) and a sample of age- and IQ-matched unaffected peers (n = 11) were evaluated on a battery of executive function (EF) measures. In addition, a "non-executive function" task, recognition memory, was administered to all subjects. Group comparisons demonstrated that PKU children were significantly impaired on an executive function composite score; there were no group differences, however, in recognition memory. These results supported the hypothesized specific deficit in executive function. Furthermore, within the PKU group the executive function composite score was significantly negatively correlated with concurrent phenylalanine levels, even after controlling for the correlation between IQ and executive function skills. This second finding provides support for the proposed biochemical mechanism underlying the specific cognitive deficits.

Child, Preschool↗
PubMed1984

Impact of PKU on the reproductive patterns in collaborative study families.

Factors that relate to reproductive patterns in 129 families after the birth of a child with phenylketonuria (PKU) include birth order of the index child, age of the parents at the birth of the index child, and expressed intentions of the parents whether or not to have additional children. Factors that do not correlate with reproductive histories include knowledge of the genetic and metabolic nature of PKU, the relationship of PKU to mental retardation and special diet, parental upset about the diagnosis, sex of the affected child, parental IQ, religion, education, and social class. Correlations found related to the question, "Is PKU the reason you don't want more children?" include stress factors in family functioning, mother's upset with the diagnosis, father's concerns about being a carrier, sex of the child with PKU, and degree of knowledge about PKU. Many of the Collaborative Study clinics tend to be more concerned about the consequences of PKU on the family than on society, and feel that families should receive genetic counseling to determine their reproductive risks and future plans. Upon self-report, many clinics declare their counseling to be either "completely nondirective" or making a "conscious effort to be nondirective."

Birth Order↗
PubMedDate not supplied

Maternal phenylketonuria: an international study.

Maternal phenylketonuria (PKU) syndrome results in multiple congenital anomalies in the offspring, usually consisting of microcephaly, intrauterine growth retardation, dysmorphology, and congenital heart disease. Pregnancies treated preconceptionally with a phenylalanine-restricted diet and control of maternal blood phenylalanine levels within the recommended range result in normal offspring. However, in this 15-year study, several significant factors resulted in microcephaly in 27% of the offspring, and 7% exhibited serious congenital heart disease. These results occurred chiefly in women with mean IQ scores of 83 associated with low socioeconomic status and decreased educational achievement. Another important factor associated with suboptimal control of blood phenylalanine levels during pregnancy was the fact that most pregnancies were not carefully planned and occurred in women off dietary treatment with phenylalanine-restricted products. These results indicate that greater effort must be developed to assist women with PKU in remaining on diet during their reproductive years. It appears that continued adherence to the diet, resulting in normal maternal intelligence, is an important contribution to improved fetal development.

Female↗