title: Maternal phenylketonuria collaborative study, obstetric aspects and outcome: the first 6 years.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: National Institute of Child Health and Human Development, Bethesda, Maryland.
authors.forename: L D
authors.initials: LD
authors.lastname: Platt
authors.forename: R
authors.initials: R
authors.lastname: Koch
authors.forename: C
authors.initials: C
authors.lastname: Azen
authors.forename: W B
authors.initials: WB
authors.lastname: Hanley
authors.forename: H L
authors.initials: HL
authors.lastname: Levy
authors.forename: R
authors.initials: R
authors.lastname: Matalon
authors.forename: B
authors.initials: B
authors.lastname: Rouse
authors.forename: F
authors.initials: F
authors.lastname: de la Cruz
authors.forename: C A
authors.initials: CA
authors.lastname: Walla
mesh_terms: D000013:Congenital Abnormalities / Q000209:etiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008499:Medical Records; D010649:Phenylalanine / Q000097:blood; D017042:Phenylketonuria, Maternal / Q000150:complications / Q000178:diet therapy / Q000503:physiopathology*; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome; D011446:Prospective Studies; D012016:Reference Values
chemical_list: D010649:Phenylalanine