It’s going to be a big week for Serena Williams.

In addition to worrying about US Open matches and dress code, the 36-year-old tennis pro is gearing up for her daughter’s first birthday. Alexis Olympia Ohanian Jr will turn one on September 1.

Serena and husband Alexis Ohanian won’t be throwing an over-the-top birthday bash for their baby girl, however. In fact, they won’t be throwing a party at all.

Serena Williams won't be celebrating her daughter, Alexis Olympia Ohanian Jr's, birthday due to her Jehovah's Witness faith

‘Olympia doesn’t celebrate birthdays,’ Serena revealed during the US Open. ‘We’re Jehovah’s Witnesses, so we don’t do that.’

According to JW.Org, Jehovah’s Witnesses don’t celebrate birthdays because such celebrations ‘have pagan roots’.

The site states: ‘According to Funk & Wagnalls Standard Dictionary of Folklore, Mythology, and Legend, these celebrations originated from the belief that on a person’s birthday, “evil spirits and influences have the opportunity to attack the celebrants” and that “the presence of friends and the expression of good wishes help to protect the celebrant”.’

What’s more, the site claims that ‘early Christians did not celebrate birthdays’ and the ‘the only commemoration that Christians are required to keep involved, not a birth, but a death — that of Jesus.’

Want to know more? Here’s what you need to know about Serena Williams’s religion, her family and more.

What religion is Serena Williams?

Serena Williams is a Jehovah’s Witness. She’s spoken openly about her faith in the past, telling Vogue in 2017: ‘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.’

Serena has been a Jehovah’s Witness since her mother, Oracene, converted to the religion in the 1980s. She says she attends church and, in the past, has gone door to door evangelizing.

Speaking on her faith in 2002 with ASAP Sports, Serena said: ‘I am Jehovah’s Witness. If you don’t believe in God — I think if you don’t believe in God, it’s going to be tough to live life because pretty much that’s the basis of life, it comes from God. And so being a Jehovah’s Witness, obviously we believe in God and the bible. And without Him, I wouldn’t be here right now. I really thank Him for everything.’

Who is Serena Williams married to?

Serena Williams is married to Reddit founder Alexis Ohanian. He is not a Jehovah’s Witness.

In fact, Serena previously said Alexis didn’t grow up particularly religious. He is comfortable with his wife’s faith, however.

According to Vanity Fair, Serena’s religion actually played a role in Alexis’s decision to propose to her. The tennis pro, who’s forbidden from participating in birthday celebrations, called her beau to wish him a happy birthday while they were dating.

Alexis saw this gesture as Serena stepping outside her comfort zone for him and decided immediately that he wanted to marry her.

Serena Williams net worth

Serena Williams’s net worth is about $27 million (£19.8m).