title: Newborn screening for congenital adrenal hyperplasia in New Zealand, 1994-2013.
abstract: OBJECTIVE
  The objective of the study was to evaluate the efficacy of national newborn screening for severe congenital adrenal hyperplasia (CAH) in New Zealand over the past 20 years.
  
  
  METHODS
  Newborn screening for CAH is performed through the estimation of 17-hydroxyprogesterone by a Delfia immunoassay. CAH cases diagnosed in the newborn period from 1994 to 2013 were identified from Newborn Metabolic Screening Programme records.
  
  
  RESULTS
  Between 1994 and 2013, 44 neonates (28 females, 16 males) were diagnosed with CAH, giving an incidence of 1:26 727. Almost half (n = 21) of the newborns with CAH were detected solely via screening (not clinically suspected), including 21% of all affected females. Among the group solely ascertained by screening, 17-hydroxyprogesterone sampling occurred at a mean age of 3.3 days (range 2-8 d), the duration from sampling to notification was 5.2 days (0-12 d), and treatment was initiated at 12.0 days (6-122 d). Vomiting was present in 14% of those ascertained by screening, but none had hypotension or collapse at diagnosis. Increasing age at treatment was correlated with a progressive decrease in serum sodium (r = -0.56; P < .0001) and an increase in serum potassium concentrations (r = 0.38; P = .017). Compared with newborns diagnosed by screening alone, those clinically diagnosed were predominantly female (96% vs 29%; P < .0001), notification occurred earlier (4.8 vs 8.5 d; P = .002), and had higher serum sodium (136.8 vs 130.8 mmol/L; P < .0001) and lower serum potassium (5.3 vs 6.0 mmol/L; P = .011) concentrations.
  
  
  CONCLUSIONS
  Screening alone accounted for nearly 50% cases of CAH detected in the newborn period, including a fifth of affected females, indicating that clinical diagnosis is unreliable in both genders. Symptoms were mild at diagnosis and there were no adrenal crises. This study confirms the benefits of newborn CAH screening.
authors.affiliation: Starship Children's Hospital (N.L.H., C.J.), 1023 Auckland, New Zealand; Liggins Institute (S.N.S., J.G.B.D., W.S.C., P.L.H.) and Department of Statistics (Y.J.), University of Auckland, 1142 Auckland, New Zealand; and New Zealand National Screening Unit (D.W., J.C.), Ministry of Health, 1051 Auckland, New Zealand.
authors.forename: Natasha L
authors.initials: NL
authors.lastname: Heather
authors.forename: Sumudu N
authors.initials: SN
authors.lastname: Seneviratne
authors.forename: Dianne
authors.initials: D
authors.lastname: Webster
authors.forename: José G B
authors.initials: JG
authors.lastname: Derraik
authors.forename: Craig
authors.initials: C
authors.lastname: Jefferies
authors.forename: Joan
authors.initials: J
authors.lastname: Carll
authors.forename: Yannan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Wayne S
authors.initials: WS
authors.lastname: Cutfield
authors.forename: Paul L
authors.initials: PL
authors.lastname: Hofman
mesh_terms: D000312:Adrenal Hyperplasia, Congenital / Q000175:diagnosis* / Q000191:economics / Q000453:epidemiology; D003362:Cost-Benefit Analysis; D005260:Female; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening / Q000191:economics / Q000592:standards; D009520:New Zealand / Q000453:epidemiology; D015397:Program Evaluation