title: Birth prevalence of cleft lip and palate in Northern Ireland (1981 to 2000).
abstract: OBJECTIVE
  The prevalence of cleft lip and/or palate (CL/P) in Northern Ireland (NI) was last reported for 1980 through 1990. This study was undertaken to update the prevalence of CL/P in NI for the 20-year period 1981 to 2000, to determine the pattern of prevalence, and to report the proportion of different cleft types and sex distribution.
  
  
  METHODS
  Retrospective, population-based analysis.
  
  
  METHODS
  All live born children with CL/P in NI from 1981 to 2000 were included. A total of 750 cases were identified. Resident births outside NI, stillbirths, abortuses, and children born with atypical orofacial clefts were excluded. Those with syndromes and submucous clefts were included in the study.
  
  
  RESULTS
  The overall prevalence of children born with CL/P within NI for the period 1981 to 2000 was 1.47 per 1000 live births, or 1:682. This was consistent with the findings reported by other U.K. studies. There were no significant changes in the prevalence rates over any 5-year period. No significant seasonality trends were noted. Clefts of the palate only were always in the majority. More boys than girls were affected by cleft lip with or without cleft palate. There was a significant left-sided predilection for unilateral clefting of the lip.
  
  
  CONCLUSIONS
  There have been no significant changes in the birth prevalence of children born with CL/P or the distribution or laterality of cleft type in the NI population during the past 20 years.
authors.affiliation: Royal Belfast Hospital for Sick Children, 180 Falls Road, Belfast, Ireland. terry.gregg@royalhospitals.n-i.nhs.uk
authors.forename: T A
authors.initials: TA
authors.lastname: Gregg
authors.forename: A G
authors.initials: AG
authors.lastname: Leonard
authors.forename: C
authors.initials: C
authors.lastname: Hayden
authors.forename: K E
authors.initials: KE
authors.lastname: Howard
authors.forename: C F
authors.initials: CF
authors.lastname: Coyle
mesh_terms: D001723:Birth Rate; D002971:Cleft Lip / Q000145:classification / Q000453:epidemiology*; D002972:Cleft Palate / Q000145:classification / Q000453:epidemiology*; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D050498:Live Birth / Q000453:epidemiology; D008297:Male; D009660:Northern Ireland / Q000453:epidemiology; D011159:Population Surveillance; D015995:Prevalence; D012189:Retrospective Studies; D017678:Sex Distribution; D050497:Stillbirth / Q000453:epidemiology; D013577:Syndrome; D006113:United Kingdom / Q000453:epidemiology