Kardashian and husband Kanye West welcomed their fourth child on May 10.
The Keeping Up With the Kardashians star shared the photo of Psalm smiling on social media on Wednesday.
“I meannnnn my baby Psalm is so sweet!!!” Kardashian captioned the post.
Baby Psalm joins the clan of North, 6, Saint, 3, and Chicago, 1. Both Chicago and Psalm were born via a gestational carrier.
On June 17, Kardashian posted a photo of Saint and Psalm together, writing: “My boys.”
The couple made the decision to have their third and fourth children through a surrogate after Kardashian suffered placenta accreta during her pregnancy with Saint.
WATCH: Kim Kardashian shares first pic of new baby named Psalm
The condition means that another pregnancy for the Selfish author could be life-threatening.
Placenta accreta is a serious pregnancy condition that occurs when blood vessels and other parts of the placenta grow too deeply into the uterine wall, according to the Mayo Clinic.
The placenta typically detaches from the uterine wall after childbirth. With placenta accreta, part of the placenta remains firmly attached. This can cause severe blood loss after delivery.
The condition is considered a high-risk pregnancy complication.
“My doctor had to stick his entire arm in me and detach the placenta with his hand, scraping it away from my uterus with his fingernails. How disgusting and painful!!!” Kardashian wrote in her blog about giving birth to her first child, North, while dealing with the condition.
“My mom was crying; she had never seen anything like this before. My delivery was fairly easy, but then going through that — it was the most painful experience of my life! They gave me a second epidural but we were racing against time so I just had to deal.”
She also suffered from preeclampsia with her first pregnancies. According to the Mayo Clinic, preeclampsia is a pregnancy complication characterized by high blood pressure and signs of damage to other organs, most often the liver and kidneys. It usually begins after 20 weeks of pregnancy in women whose blood pressure had previously been normal.
If preeclampsia is left untreated, it can lead to serious or even fatal complications for both the baby and the mother.
—With a file from Arti Patel