Serena in inspirational message to working mums

Serena Williams has posted an inspirational New Year message to mums and dads juggling parenthood with work, saying "anything is possible".

The 23-time Grand Slam champion began 2019 in Perth at the mixed teams Hopman Cup, with baby Alexis Olympia in tow.

She posted a picture of herself and her daughter to her 10.4 million followers on Instagram, holding her child as she stretched her leg.

Williams, 37, said "it's not about what we can do it's what we MUST do as working moms and working dads".

"Anything is possible. I was getting ready for the first match of the year and my dear sweet baby @olympiaohanian was tired and sad and simply needed mama's love.

"So if it means warming up and stretching while holding my baby that's what #thismama will do.

"My fellow moms and dads working - or stay home it's equally as intense - but you inspire me," she added.

"Hearing your stories makes me know I can do this. Thank you from the bottom of my heart. This year is to you!"