On the basis of that timescale it means that Williams won the Australian Open in January - her 23rd grand slam singles title - in the first few weeks of her pregnancy.

Williams, who announced her engagement to Reddit co-founder Ohanian in December, has not played on tour since winning in Melbourne as she pulled out of high-profile tournaments in Indian Wells and Miami, blaming a knee injury.

Her representatives have confirmed to Press Association Sport that she will not feature in any more tournaments this year, but is planning a return in 2018.

In a strange oddity in the rankings Williams will climb back to the world number one spot on Monday, despite three months of inactivity.

Confirming the pregnancy several hours after Williams' Snapchat picture went viral, her spokesperson said: " I'm happy to confirm Serena is expecting a baby this Fall."

The well-wishes poured in after the confirmation, with fellow American Andy Roddick tweeting: "There's going to be a baby GOAT (greatest of all time). We are so happy and we know @serenawilliams will be a great mother."

Chris Evert also said on Twitter: "A baby and a wedding? A VERY special year ahead for @serenawilliams So happy for her new journey..."

By aiming to return to the game, Williams will follow in the footsteps of Victoria Azarenka, who is close to heading back on tour after the birth of her first child Leo in December.

The former world number one is pencilled in to make her comeback at the Bank of the West Classic in Stanford at the end of July, while Kim Clijsters also returned to the top of the game, winning the US Open in 2009 18 months after giving birth to her daughter.

CEO of the WTA Steve Simon also sent his congratulations to Williams.

He said in a statement: "We're excited for Serena. This is wonderful news and we wish her the very best.

"We'll look forward to seeing her when she's back competing again."