She stated that this is due to their beliefs as Jehovah's Witness, a religious organisation that does not celebrate birthdays.

She revealed this at a press conference at the US Open Serena Williams' adorable daughter, Alexis Olympia turns a year old on September 1, 2018. Unfortunately for fans of the couple, there won't be any birthday celebration or adorable birthday photos for the 'gram, according to Serena's recent revelation. The tennis champion revealed that Olympian won't be celebrating her birthday as they belong to Jehovah's Witness church, a religious organisation that does not believe in birthday celebrations. She revealed this at a press conference at the US Open. Responding to a reporter who asked if there would be any birthday celebrations for her daughter, the 36-year-old had this to say: "Olympia doesn’t celebrate birthdays. We’re Jehovah’s Witnesses, so we don’t do that."

‘Speaking to Vogue last year, she had this to say: "Being a Jehovah’s Witness is important to me, but I’ve never really practiced it and have been wanting to get into it. ‘Alexis didn’t grow up going to any church, but he’s really receptive and even takes the lead. He puts my needs first."

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