World number nine Danielle Collins will return to action next year after previously announcing she would retire at the end of the 2024 season.
The 30-year-old American continues to deal with endometriosis, which can affect fertility, and told BBC Sport in May that starting a family was "one of her biggest goals outside of tennis".
Collins posted on Instagram: "The Danimal story has not reached its conclusion. I will be back on tour in 2025."
She said while she had been "excited and eager" to end her tennis career "on a high note" this year and "jump headfirst into my next chapter of life", things have not gone as planned.
Describing starting a family as her "ultimate dream", she said as well as managing some lingering health challenges during the past few months, she has been seeing specialists to help understand her best path forward.
She added: "Dealing with endometriosis and fertility is a massive challenge for many women and something that I am actively traversing, but I am fully confident in the team I am working with. It is just going to take longer than I thought."
Collins' announcement came on the same day she was listed on the entries for the season-opening United Cup in Australia, which takes place from 27 December to 5 January.
The 2022 Australian Open finalist won back-to-back tournaments in Miami and Charleston in March and April amid a strong run of form.
However, she has not competed since losing to world number 152 Olivia Gadecki in Guadalajara on 11 September - her fourth successive defeat since reaching the quarter-finals at the Paris 2024 Olympics.