female:male ratio in K-3 kids

[jcoleman at msvax.mssm.edu]

In article <4d3olr$dnp at ccshst05.cs.uoguelph.ca>, jkassie at uoguelph.ca (Jennifer S Kassie) writes:
>Sophie Wilson (sophiewi at uoguelph.ca) wrote:
>: And I dimly remember from a biology class that as women 
>: age, they are more likely to produce female babies than male babies.  Is 
>: it possible that the average age of the MOTHERS might be a factor here?
>
>
>But doesn't the male (who carries both X and Y chromosomes) determine the 
>sex of the baby?  Females can ONLY contribute an X chromosme.  
>
>--
>---------------------------------------------------------------------------
>     ***************************             ---///-   /
>    *     Jenn Kassie         *      o<    / o     \//
>   *  jkassie at uoguelph.ca    *         o<  )       /\\
>  * Guelph, Ontario, Canada *               ----\\-    \ 
> ***************************
This is true genetically of course...but I remember something about
vaginal/uterine pH being a factor...or something...I think changes in the
uterine environment may be selective for X versus Y sperm maybe? Of course this
may be an old wives' tale :-)

Jen