The 34-year-old German, who won at SW19 in 2018, revealed the news on the eve of this year's US Open - a tournament she won in 2016.
She will now take a step back from the game meaning she will miss out at Flushing Meadows.
She said on Twitter: "I really wanted to play the US Open but eventually I decided that two against one just isn't a fair competition.
"For the next months, I will take a break from travelling the globe as a tennis player but then again, I believe it's for the best possible reason I will miss all of you.
"New York has often been a turning point in my career and it feels like this year will be no different in some way! From restarting my career in 2011 to winning the title in 2016 and becoming number one in the world.
"The US Open has a special place in my heart and I wish I could have said goodbye to all of you on court before not being around on tour for a while.
"Being a professional athlete means everything to me but I'm grateful for the new path I'm heading to. To be honest, I'm nervous and excited at the same time. Thanks for your continued support - it means everything to me."