1/9. Undiagnosed maternal phenylketonuria: the need for prenatal selective screening or case finding.OBJECTIVES: The aims of this article are to report on a review of cases of maternal phenylketonuria in the International Maternal Phenylketonuria Collaborative Study that were initially diagnosed during or after a pregnancy, to alert health care practitioners to the possible existence of women with undiagnosed phenylketonuria whose fetuses are at risk, and to emphasize that not all adults with untreated phenylketonuria are mentally retarded. STUDY DESIGN: The study was conducted through retrospective database review. RESULTS: Of 414 women with live-born infants, 17 fulfilled our criteria. Six had phenylketonuria diagnosed after they had produced >/=1 affected offspring, 2 had phenylketonuria diagnosed as a result of transient postnatal hyperphenylalaninemia in an offspring, and 9 had phenylketonuria diagnosed by prenatal screening. Undiagnosed maternal phenylketonuria in north america and europe is currently estimated at 1 case/100,000 births; this rate could be higher elsewhere. CONCLUSIONS: physicians and midwives should consider a protocol of selective prenatal screening or case finding to detect undiagnosed phenylketonuria among their patients.- - - - - - - - - - ranking = 1keywords = pregnancy (Clic here for more details about this article) |
2/9. Repeated adverse fetal outcome in pregnancy complicated by uncontrolled maternal phenylketonuria.Phenylketonuria in pregnancy carries with it an increased risk of spontaneous abortion and development of a fetus that is affected by the maternal phenylketonuria syndrome. This syndrome is characterized by low birthweight, congenital heart disease, microcephaly, childhood growth failure, and cognitive impairment. It is the result of the hyperphenylalaninemia that accompanies the phenylketonuric state, and may therefore be avoided by maintaining maternal serum phenylalanine levels within the normal range. Phenylalanine is an essential amino acid and may be controlled by dietary manipulation. Presented here is a case history of a woman with phenylketonuria who was unable to satisfactorily control her serum phenylalanine levels in each of her three pregnancies. All three children were adversely affected by the fetopathy of the maternal phenylketonuria syndrome, each with evidence of growth failure and impaired neurodevelopment. This patient illustrates the difficulties that may be encountered when providing obstetric care to the woman with phenylketonuria who is not able or not willing to restrict her dietary intake of phenylalanine. The discussion includes consideration of management strategies, including dietary therapy and legal intervention.- - - - - - - - - - ranking = 5keywords = pregnancy (Clic here for more details about this article) |
3/9. Nutritional factors affecting serum phenylalanine concentration during pregnancy for identical twin mothers with phenylketonuria.The effect of energy, protein, fat, and phenylalanine on serum phenylalanine concentrations during pregnancy for a set of identical twins with phenylketonuria (PKU) was examined. blood samples were collected one to two times per week. The subjects completed a 3-d food record prior to each blood collection. The effect of the factors on serum phenylalanine levels was evaluated statistically using time-series analysis. Dietary intakes of the nutrients evaluated were similar for the subjects. For one subject, there were highly significant effects of energy, protein, and fat on serum phenylalanine levels. In contrast, these nutrients had no significant effect on serum phenylalanine for the other subject. Dietary phenylalanine had no significant effect on serum phenylalanine for either twin. CONCLUSIONS: There was no effect of phenylalanine intake and no consistent effect of energy, protein, or fat on serum phenylalanine. Other dietary or environmental factors or a combination of factors may impact serum phenylalanine levels of pregnant women with PKU.- - - - - - - - - - ranking = 5keywords = pregnancy (Clic here for more details about this article) |
4/9. Barriers to dietary control among pregnant women with phenylketonuria--united states, 1998-2000.Newborns in the united states are screened for phenylketonuria (PKU), a metabolic disorder that when left untreated is characterized by elevated blood phenylalanine (phe) levels and severe mental retardation (MR). An estimated 3,000-4,000 U.S.-born women of reproductive age with PKU have not gotten severe MR because as newborns their diets were severely restricted in the intake of protein-containing foods and were supplemented with medical foods (e.g., amino acid-modified formula and modified low-protein foods). When women with PKU do not adhere to their diet before and during pregnancy, infants born to them have a 93% risk for MR and a 72% risk for microcephaly. These risks result from the toxic effects of high maternal blood phe levels during pregnancy, not because the infant has PKU. The restricted diet, which should be maintained for life, often is discontinued during adolescence. This report describes the pregnancies of three women with PKU and underscores the importance of overcoming the barriers to maintaining the recommended dietary control of blood phe levels before and during pregnancy. For maternal PKU-associated MR to be prevented, studies are needed to determine effective approaches to overcoming barriers to dietary control.- - - - - - - - - - ranking = 3keywords = pregnancy (Clic here for more details about this article) |
5/9. Normal infant by a gestational carrier for a phenylketonuria mother: alternative therapy.The consequences of pregnancies in untreated phenylketonuria (PKU) mothers are a high incidence of spontaneous abortion, intrauterine growth retardation with microcephaly, congenital malformations, and abnormal intellectual development. PKU fathers, on the other hand, produce normal children. Obviously children of PKU women and men are at least heterozygous, proving that the abnormalities produced by the PKU mothers are not genetic but "intrauterinely environmental." Exposure to the mother's metabolic abnormalities affects the fetus during the entire pregnancy. A PKU mother can produce a healthy infant if she maintains a very restricted and controlled diet before and during pregnancy. However, even the most recent reports describe a very high incidence of congenitally abnormal children of PKU mothers, hence dietary compliance is not working in all cases. A 26-year-old PKU patient with proven fertility underwent standard ovarian stimulation in preparation for oocyte retrieval. Following conventional co-incubation of the oocytes and her husband's sperm, two embryos were transferred to the gestational carrier's uterine cavity, resulting in a single intrauterine pregnancy. Birth was induced at 39 weeks of gestation. The male infant weighed 3486 g. head circumference was 36 cm and length 50.5 cm; there was no evidence of any abnormality and/or malformation. At 1 year of age, the child's growth measurements and development assessments were normal. This describes the first reported successful term pregnancy of an untreated PKU mother with the help of a gestational carrier (GC), producing a normal infant. This is an alternative method that should be offered to PKU women who are unable and/or unwilling to maintain a well controlled diet before and during pregnancy.- - - - - - - - - - ranking = 5keywords = pregnancy (Clic here for more details about this article) |
6/9. An exceptional Albanian family with seven children presenting with dysmorphic features and mental retardation: maternal phenylketonuria.BACKGROUND: Phenylketonuria is an inborn error of amino acid metabolism which can cause severe damage to the patient or, in the case of maternal phenylketonuria, to the foetus. The maternal phenylketonuria syndrome is caused by high blood phenylalanine concentrations during pregnancy and presents with serious foetal anomalies, especially congenital heart disease, microcephaly and mental retardation. CASE PRESENTATION: We report on an affected Albanian woman and her seven children. The mother is affected by phenylketonuria and is a compound heterozygote for two pathogenetic mutations, L48S and P281L. The diagnosis was only made in the context of her children, all of whom have at least one severe organic malformation. The first child, 17 years old, has a double-chambered right ventricle, vertebral malformations and epilepsy. She is also mentally retarded, microcephalic, exhibits facial dysmorphies and small stature. The second child, a girl 15 years of age, has severe mental retardation with microcephaly, small stature and various dysmorphic features. The next sibling, a boy, died of tetralogy of fallot at the age of three months. He also had multiple vertebral and rib malformations. The subsequent girl, now eleven years old, has mental retardation, microcephaly and epilepsy along with facial dysmorphy, partial deafness and short stature. The eight-year-old child is slightly mentally retarded and microcephalic. A five-year-old boy was a premature, dystrophic baby and exhibits mental retardation, dysmorphic facial features, brachydactyly and clinodactyly of the fifth finger on both hands. Following a miscarriage, our index case, the youngest child at two years of age, is microcephalic and mentally retarded and shows minor facial anomalies. All children exhibit features of phenylalanine embryopathy caused by maternal phenylketonuria because the mother had not been diagnosed earlier and, therefore, never received any diet. CONCLUSION: This is the largest family suffering from maternal phenylketonuria reported in the literature. Maternal phenylketonuria remains a challenge, especially in woman from countries without a neonatal screening program. Therefore, it is mandatory to be alert for the possibility of maternal phenylketonuria syndrome in case of a child with the clinical features described here to prevent foetal damage in subsequent siblings.- - - - - - - - - - ranking = 1keywords = pregnancy (Clic here for more details about this article) |
7/9. Tetrahydrobiopterin and maternal PKU.A 29-year-old woman with PKU is presented, who was successfully treated with phenylalanine restriction as well as oral BH4 during this pregnancy, with a normal outcome. Her PAH mutation was R408W/F39L. Remarkably, the blood phenylalanine control was easily accomplished during this pregnancy. The lack of nausea and vomiting during the first trimester suggests that the occurrence of CHD in babies born to women with PKU may be reduced with BH4.- - - - - - - - - - ranking = 2keywords = pregnancy (Clic here for more details about this article) |
8/9. pregnancy in phenylketonuria: dietary treatment aimed at normalising maternal plasma phenylalanine concentration.The transport characteristics of the placenta, which favour higher phenylalanine concentrations in the fetus than in the mother, and regression data of head circumference at birth against phenylalanine concentration at conception in maternal phenylketonuria (PKU), suggest that treatment of maternal PKU should ideally aim to maintain plasma phenylalanine concentration within the normal range throughout pregnancy. A patient with classical PKU was treated from before conception by aiming to maintain plasma phenylalanine concentration within the range 50-150 mumol/l and tyrosine within the range 60-90 mumol/l. The diet was supplemented with phenylalanine-free amino acids (100-180 g/day) and tyrosine (0-5 g/day). plasma amino acid concentrations were monitored weekly by amino acid analyser. Dietary phenylalanine intake ranged from 6 mg/kg/day at conception to 30 mg/kg/day at delivery. Normal weight gain and fetal growth were maintained throughout the pregnancy. A normal baby was born at term with a head circumference of 35.5 cm; at 1 year of age no abnormality is detectable. These results show that with careful monitoring and compliance it is possible, and may be advisable, to maintain plasma phenylalanine concentration within the normal range in the management of PKU pregnancy.- - - - - - - - - - ranking = 3keywords = pregnancy (Clic here for more details about this article) |
9/9. Mild hyperphenylalaninemia and heterozygosity of the phenylalanine hydroxylase gene.Newborn screening for phenylketonuria (PKU) is now the standard of practice. Initial phenylalanine blood levels of 240 mumol/L result in referral of affected newborns to medical facilities experienced in caring for patients with metabolic disorders. This case report concerns a female infant born in 1976 with a presumptive positive PKU screening test on the third day of life of 240 mumol/L phenylalanine. Follow-up levels while the mother was breast feeding on the sixth day of life were 324 and, on the 27th day, 312 mumol/L. She was subsequently lost to follow-up at age 11 years, but returned at 19 years of age due to pregnancy, with a blood phenylalanine level of 132 mumol/L. mutation studies then were performed documenting that she was a carrier for the phenylalanine hydroxylase gene and did not have hyperphenylalaninemia. The mother's parents and the infant were also genotyped confirming heterozygosity. The infant on follow-up is completely normal, following a normal pregnancy.- - - - - - - - - - ranking = 2keywords = pregnancy (Clic here for more details about this article) |