Serena Williams is pregnant and glowing. After surprising her fans earlier this month with the good news, she recently penned down an emotional message for her unborn baby.

According to Mail Online, Serena Williams announced that she will not take part in any tournaments this year due to her pregnancy. She then wrote a beautiful letter dedicated to her baby stating how excited she is.

"My Dearest Baby, You gave me the strength I didn't know I had. You taught me the true meaning of serenity and peace," Mail Online quoted Serena Williams. "I can't wait to meet you. I can't wait for you to join the players' box next year."

Serena Williams continued that she is very happy to have shared the number one position in the world with her baby, twice. She called herself "world's oldest number one" and her baby "world's youngest number one".

Earlier this month, Serena Williams shared a selfie on social media that showed off her baby bump with the caption and with the caption '20 weeks'. Although the post was deleted shortly afterward, her Los Angeles-based publicist Kelly Bush Novak confirmed that the tennis player is indeed expecting her first baby.

According to The Guardian, fans were amazed to learn that Serena Williams was eight weeks pregnant when she won this year's Australian Open beating her sister Venus Williams. With this win, the 35-year old is just one grand slam title short of matching Australian Margaret Court's record of 24.

Serena Williams win earned her the title of the most successful tennis player in the professional era and she moved ahead of Steffi Graf. Recently, she was again placed in the first position, taking the title away from Germany's Angelique Kerber.

Serena Williams is currently taking her time off in Mexico with fiancé, Reddit co-founder Alexis Ohanian. However, her message to her unborn baby clearly indicates that the player will return to her career after giving birth.