The 36-year-old tennis star gave birth to her first child, Alexis Olympia, in September. Picture: AP

London - Faced with worries about breastfeeding, sleep and establishing a healthy balance between work and parenthood, some new moms struggle during the first months of their baby’s life,

So spare a thought for Serena Williams, who has put the worst loss of her 20-year tennis career down to post-natal emotions.

The seven-time Wimbledon champion admitted she wasn’t around as much as she’d like for her 11-month-old daughter because of her demanding training regime.

The 36-year-old tennis star gave birth to her first child, Alexis Olympia, in September. But in a post on her Instagram page, she admitted she didn’t feel like a good mother after fearing she was not doing enough for her daughter.

She told her nine million followers: "Last week was not easy for me. Mostly, I felt like I was not a good mom. I read several articles that said postpartum emotions can last up to three years if not dealt with.

"Talking things through with my mom, my sisters, my friends let me know… it’s totally normal to feel like I’m not doing enough for my baby." The star, who married Silicon Valley millionaire Alexis Ohanian, 35, in 2017, admitted her tennis career made finding a work-life balance difficult.

She added: "I work a lot, I train, and I’m trying to be the best athlete I can be. However, that means although I have been with her every day of her life, I’m not around as much as I would like to be."

In a heart-warming message to other mothers, she added: "If you are having a rough day or week – it’s OK – I am, too."