Allison Williams has struggled to "move on" from having an emergency caesarean section four years ago.

The former Girls actress has previously spoken of the "profoundly scary moment" when medics opted for surgical intervention to bring her son Arlo into the world after being in labour for 36 hours and she has now admitted she still hasn't fully come to terms with what happened.

Sharing a link to a recent episode of her Landlines podcast, which featured guest Dr. Sarah Reardon and co-hosts Hope Kremer and Jaymie Oppenheim, Allison wrote on Instagram: "My C-Section was almost 4 years ago, and I still have lots of feelings about it.

"No two birth stories are identical. It's wild how many infinite ways this one, shared, foundational experience can play out. Mine was a lot, and I've been lucky enough to be able to process it with some wonderful doctors (including my OBGYN) afterwards. But no amount of processing will ever be enough.

"I had surgery that I didn't know I was going to have, while I was awake and tied-down to a table. How do we just move on from those things? Can we?

"Anyway, to all the other C-Section people out there: my scar is smiling at yours from across the internet."

During the podcast episode, the 37-year-old actress - who has her son with husband Alexander Dreymon - admitted she had never fully thought about giving birth in a different way to how she had planned.

She said: "I thought I had thought about, 'Oh, yeah, I might have to have a C-section, but I never actually walked myself through the moment where a doctor comes in and says, 'You're gonna need to have a surgery, awake, that you didn't know you were gonna have.

"No one talked to me about my emotional state, about managing that.

"My PT, she got my full medical file from the hospital and read the entire 200 pages of it, and, like, walked me through what happened. And it was, like, it's just a really weird … because it was all like, you know, hard for me to remember, super traumatic, and she just … sorry."

Allison then began to cry before Sarah, a pelvic floor physical therapist, intervened to offer support and reassurance.

She said: "You're not alone. You sharing this gives other moms the ability to feel seen, because so many people go through that and they don't unpack it totally, and we hold it with us for a really, really, really long time."