title: The male to female ratio at birth in the Republic of Ireland and Northern Ireland: influence of societal stress.
abstract: BACKGROUND
  Male live births occur slightly in excess of female births. The ratio of male divided by total births is referred to as M/F. Many factors reduce M/F including toxins, stress, and privation, with excess male foetal loss. "The Troubles" (1969-1998) of Northern Ireland (NI) and the economic downturn of Republic of Ireland (ROI) from 2007 posed stresses with corresponding controls. This study analysed M/F in NI and ROI.
  
  
  METHODS
  Annual male and female live births in NI and the ROI were compared using chi tests.
  
  
  RESULTS
  M/F was significantly higher in NI than in ROI. M/F in NI dropped after 1974. M/F rose in ROI up to 1994, then fell.
  
  
  CONCLUSIONS
  Violence-related stress may have been the cause for the M/F drop in NI. Economic improvement followed by recession may have caused parallel M/F changes in ROI. These findings agree with the stress hypothesis of M/F.
authors.affiliation: Academic Department of Paediatrics, Medical School, Mater Dei Hospital, Malta.
authors.forename: Victor
authors.initials: V
authors.lastname: Grech
mesh_terms: D002960:Civil Disorders; D057172:Economic Recession; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007494:Ireland; D050498:Live Birth; D008297:Male; D009660:Northern Ireland; D012744:Sex Ratio