Five-year-old Jack, who she shares with ex-husband Chris Pratt, was born two months prematurely resulting in a number of medical complications.
“When Jack was born two months early, it came as a huge shock. And suddenly, your world completely shifts,” Anna explained.
“Jack had a few surgeries. He had a few hernia surgeries, he’s had a few eye surgeries, and he had a little heart issue as well.”
The 41-year-old has previously spoken about the moment they found out about Jack’s health complications in her book Unqualified.
“The paediatric neurosurgeon sat Chris and me down to tell us that Jack had some severe brain bleeding and there was a chance that he could be developmentally disabled,” Anna wrote. “I was in complete shock… So Chris and I did what we could, which was hold hands and hope and face it together.”
She said that Chris was "amazing" throughout the experience.
“He decorated my room with posters and photos and he came to the hospital every night after work with desserts for me and, sometimes, a six-pack of beer for himself, and he’d just sit with me and hold my hand or crawl into bed,” she wrote.
The harrowing ordeal lead the pair to become involved with the Global Alliance to Prevent Prematurity and Stillbirth, a group aiming to end premature and stillborn childbirths.
"The doctors and nurses that helped us and surrounded us were so unbelievably supportive that it inspired Chris and I and my parents to all get involved in this."