04/24/2017 03:28 EDT

Serena Williams Publicly Acknowledges Pregnancy With Letter To Baby

In the first public acknowledgement of her pregnancy, Serena Williams posted an Instagram letter to her future baby on Monday that was equal parts vulnerable and inspiring.

Williams, 35, who had put up a Snapchat last week with the caption "20 weeks," only to take it down right after, has stayed quiet since (though her publicist confirmed the news). But she's obviously looking forward to having this baby with fiancé Alexis Ohanian, who celebrates his birthday today.

"You gave me the strength I didn’t know I had," she wrote in her post. "But most importantly, I am so happy to share being number one in the world with you ... from the world's oldest number one to the world's youngest number one. -Your Mommy."

The No. 1 was in reference to the news today that Williams has reclaimed the ranking thanks to a calendar glitch that saw Angelique Kerber drop to No. 2 for the time being, reports

Williams plans to take off the rest of the season and go back on tour next year.

But she wasn't the only member of the couple to get public about their upcoming baby. Ohanian, the co-founder and current executive chairman of Reddit, shared his own post with a drawing of him and Williams done up as Reddit Snoos, the mascot of the site.

He also took the opportunity to recognize Armenian Genocide Remembrance Day, a topic he'd recently discussed in an open letter to the Reddit community after U.S. President Trump's executive order banning people from specific countries.

"A little over a century ago, a Turkish soldier decided my great grandfather was too young to kill after cutting down his parents in front of him; instead of turning the sword on the boy, the soldier sent him to an orphanage," he wrote on the site. "Many Armenians, including my great grandmother, found sanctuary in Aleppo, Syria — before the two reconnected and found their way to Ellis Island.

"My forebears were brave refugees who found a home in this country. I’ve always been proud to live in a country that said yes to these shell-shocked immigrants from a strange land, that created a path for a woman who wanted only to work hard and start a family here."

Today, as he celebrated the news of his child who will be arriving in the fall, he asked for people to "always remember the sacrifices our predecessors made; honour them through our successes; and appreciate our blessings."