The changes address issues that arose this year when Serena Williams, who returned to the action after giving birth to her daughter, was unseeded for some events and caused an uproar with a black, skin-tight bodysuit she wore at the French Open.
The new rules will allow players out of competition for 52 weeks or longer to use their Special Ranking in 12 tournaments.
A player returning from pregnancy will have a three-year period to use her Special Ranking, which will now begin at the birth of the child.
