Selecting the sex of your baby is basic science. 

The basic facts are:

- women produce one kind of egg.
- men produce two kinds of sperms: Y = male and  X=female  The sperm that reaches the egg and
  fertilizes it decides the sex of the baby.
- Y sperm is fast, slimmer, weaker
- X sperm is slow, fat, stronger
- Other factors are:
                - man's diet and conditioning prior to intercourse to promote over all sperm count and a specific sperm gender.
                - Woman's acidity and conditioning.
                - accurately determining ovulation date
                - controlling the distance and the conditions between ejaculated sperms and the egg.
               

Though we would be glad to explain, educate, illustrate and advise; due to several reasons, on this site, I'll use animals (dogs artificial insemination case) to explain the issue.  I'll link you here to a page in a professional breeding site page written by one of our senior chemists.


Click here for better details.