IN THIS ISSUE (see pages 37 to 41) Dr. Bruce B. Allan and associates r
eport a small but statistically significant decrease - of about 0.2% -
in the proportion oi male live births in Canada over the period 1970
- 90. In this editorial, factors that have been reported in the litera
ture to influence sex ratio are examined within a Canadian context. Th
e authors suggest that although the reasons for the apparent decline i
n the sex ratio in Canada are unclear, the increasing use of ovulation
induction may be a contributing factor, Data from the Nova Scotia Atl
ee Perinatal Database are discussed with a view to explaining the tren
d observed in Atlantic Canada, but no obvious explanation emerges. The
authors argue that when the period of observation is extended no over
all change in the sex ratio is apparent. This would suggest a tendency
toward stabilization rather than decline.