Katherine Heigl shares baby bump photo as she recalls son's harrowing birth: 'I thanked the heavens'

Katherine Heigl, who welcomed her first son Joshua Jr with husband Josh Kelley around this time last year, has opened up on Instagram about her harrowing experience with a caesarean section delivery.

Sharing a series of sweet throwbacks – including a baby bump photo taken right before the delivery – the mother-of-three detailed the dramatic birth of her son, who celebrated his first birthday on Wednesday, 20 December.

"At 9am one year ago today I had @joshbkelley take this photo of me so I could remember how incredibly pregnant I was right before we left for the hospital and my 12pm scheduled caesarean," Heigl shared, alongside the series of photographs before and after the birth of young Joshua.

Recalling the difficulties she faced, the Grey's Anatomy actress continued, "Joshua Jr had been in the breech position for over a month and had still not moved an inch a week before his due date so I made the decision to have a cesarean and was incredibly nervous and a little scared this time last year."

"I had never been hospitalised or had ever had any kind of surgery and had no idea what to expect," added Heigl, who is also mother to two daughters - Naleigh, 7, and Adalaide, 4 – whom she adopted in 2009 and 2012 respectively.

In a second photo, the Hollywood actress documented the moment right before she got into surgery, which was equally difficult as the "doctor struggled to get [her son] out because he was really wedged in there and not quite ready to leave the womb". However, her struggles didn't end there.

The 39-year-old said her son didn't start breathing immediately after the delivery and the doctors had to give him oxygen to "start his tiny lungs". Her actor husband Josh was present with their son until he took his first breath.

"That day, as I slowly came out of the morphine haze and clutched my tiny man to me I thanked the heavens for his breath, his life and for making me a mother three times over," wrote the Unforgettable actress, who tied the knot with Josh in 2007.

She added, "He was so tiny and new, so fragile and tender. As I lay him down to sleep that first night in his very appropriate 'welcome to the world' sleep sack I thought the moment would last forever."

And yet, a year later as the proud mum celebrates her baby boy's first birthday, the photos are the only memory she has of the heartwarming experience. "Now he's 26 pounds of rolling, tumbling, grasping, giggling, shouting, curious, jolly energy!" she says gushing about baby Joshua.

Hoping for another treasure of memories, Heigl concluded, "Happy Birthday to my little man! Maybe I can make this next year go a little slower!"