Please look at http://en.wikipedia.org/wiki/Judit_Polgar
'...In 2004 Judit took some time off from chess to give birth. She was
consequently considered inactive and not listed on the January 2005 FIDE
rating list, meaning that her sister Zsuzsa temporarily became the world
number one woman player. Judit is expected to return to chess at the Corus
chess tournament in January 2005.'
