TMZ reports the 2-year-old went into the hospital Thursday and remained there until Saturday.
Just days before, mom of two Kim had shared a rare family snap as they celebrated Christmas together.
In the image, Kanye — who is seen smiling — is holding Saint while Kim holds their eldest child, daughter North.
The famous couple, who are expecting their third child via surrogate this year, still managed to celebrate New Year’s Eve together as Saint recovered at home.
And Kim, 37, shared footage as the clock struck midnight and she locked lips with her rapper husband.
Kanye couldn’t have looked happier as they rang in the New Year together, no doubt looking forward to what 2018 will bring for them.
Kim also revealed that having their third child was a real highlight for the couple.
Posting about her favorite moments of 2017, she shared: “In 2017, my focus was on family, travel and launching my dream businesses: KKW Beauty and KKW Fragrance.
“As the new year approaches, I feel so blessed to have had such an amazing year … Kanye and I were so excited to find out that we were expecting! I can’t wait to welcome our little girl in the new year. North and Saint will be the best big brother and sister to her.”
The Sun Online has contacted Saint’s rep for comment