While Saint is now home from the hospital and feeling much better, Kim described the experience as "so scary". "We are so grateful for you all!" she wrote, before giving her followers an update on her son's condition.
The 37-year-old says Saint is all better now, calling the little love muffin "so resilient" and using the mixed baby angel emoji.
What a scary experience - and what a awful way for the Kardashian-West family to end 2017! "Pneumonia is so scary", the Keeping Up with the Kardashians star wrote.
Taking to Twitter, Kim shared: "My precious baby boy is so strong!" On December 20, Khloé Kardashian announced that she is expecting her first child with boyfriend, National Basketball Association player Tristan Thompson.
Just days ago, Kardashian West shared a special holiday-themed family photo with West, 40, their son, and their adorable daughter North, 4.
The West family will likely find themselves back in the hospital in the next month or so when they welcome the newest addition to their family, who is being delivered by a surrogate. "So, it's definitely a harder experience than I anticipated just in the control area".