Jason Biggs and Jenny Mollen's son was rushed to an intensive care unit (ICU) after falling on his head at the weekend.
Jenny Mollen and Sid (c) Instagram
The couple - who have Sid, five, and Lazlo, 18 months, together - have had a "traumatic" few days after their eldest son fractured his skull when the 39-year-old actress dropped him, but luckily the youngster is now "recovering nicely" and has returned home.
Jenny has thanked the staff at Lennox Hill and New York-Presbyterian Hospitals for their care and help in look after their family.
She shared a selfie on Instagram - with Sid's face obscured by an emoji - and wrote: "On Saturday evening, I dropped my son on his head causing him to fracture his skull and landing him in the ICU.
"I am forever grateful to Lenox hill downtown and @nyphospital for their immediate response and aid. Thank you to all of the nurses, neurologists, pediatricians, residents, cafeteria staff and brave women that keep the visitor's bathrooms clean. Not sure how this post turned into an Oscars acceptance speech... But @biggsjason Thank god for you! Thank god, thank god, thank god.
"It has been a traumatic week but Sid is home now taking things slowly and recovering nicely. He is also eating a lot of chocolate dipped ice cream cones and plans to try cherry dipped soon."
And the 'Angel' actress sent her support to other parents who experience a similar situation.
She added: "My heart goes out to all parents who have or will ever find themselves in this kind of position. You are not alone..."
Jason hasn't yet commented on his son's injury.
Tagged in Jason Biggs Jenny Mollen