title: The Secondary Sex Ratio at Birth Was Depressed in Quebec by the Sovereignty Referendums.
abstract: BACKGROUND
  Globally, male live births exceed female live births by approximately 3%. The secondary sex ratio is conventionally expressed as male births divided by total live births (M/T). Many factors have been implicated as influencing this ratio, such as stress (including non-violent political events) and toxins, both of which reduce it. The Quebec government twice proposed referendums to its populace advising sovereignty. This study was carried out in order to ascertain whether the referendums had any effect on the M/T ratio in Quebec and in Canada as a whole.
  
  
  METHODS
  Annual births in Quebec and Canada were compared for the index (referendum) years 1980 and 1995 versus the sum of the preceding and following five year periods, for each event. The monthly M/T ratio for Quebec before and after the 1995 referendum was also calculated.
  
  
  RESULTS
  This review covered 8 099 600 live births. In Quebec, the M/T ratio was lower in the two referendum years than in the preceding and following five year periods, and was significantly lower after the 1995 referendum (P = 0.04). No significant changes were noted for Canada as a whole. Monthly calculations for Quebec showed a decline in the M/T ratio three months after the 1995 referendum (P = 0.035), followed by a rapid recovery (P = 0.001).
  
  
  CONCLUSIONS
  The second Quebec referendum on sovereignty in 1995 had a higher voter turnout than the 1980 referendum and was more closely run. Reductions in the M/T ratio have been noted in association with stressful population events, including non-violent political activities. This may have been the case in Quebec, where the M/T ratio declined in association with two referendums that proposed sovereignty, possibly due to the stress engendered by these events and the potential outcomes.
authors.affiliation: Associate Professor of Paediatrics, University of Malta, Msida, Malta.
authors.forename: Victor
authors.initials: V
authors.lastname: Grech
mesh_terms: D002170:Canada / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D011057:Politics; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology / Q000523:psychology*; D011256:Pregnancy Outcome / Q000453:epidemiology*; D011792:Quebec / Q000453:epidemiology; D012744:Sex Ratio; D013315:Stress, Psychological / Q000453:epidemiology*
keywords: Canada; Quebec; birth rate; birth trends; infant; newborn; politics; sex ratio