Penn Badgley and Domino Kirke almost broke up after their second miscarriage

Speaking on the Totally Booked with Zibby podcast, Penn said: "But I mean, especially for us, me at that point not having any biological children and my wife having her firstborn... that was a real inflection point.

"One of the greatest of my life and my wife's because we did near separation, and of course, we didn't give into the gravity of that and the sort of entropy of that.

"And here we are with three biological children since."

In September, the 39-year-old actor revealed he and the 41-year-old singer had welcomed twin boys into the world.

The Gossip Girl star was discussing his new book Crushmore: Essays on Love, Loss, and Coming-of-Age, in which he opened up about their struggles.

He wrote: "This was our second loss together. A time when it did not feel as though the cycle would break.

"My wife and I neared separation as many do after losses like that.

"Largely because we felt so isolated in a culture that doesn't talk much about these things or know how to support those going through it.

"Seeing our still baby in that tripped out black-and-white sono imagery is a dreadful memory I can't shake every time we go for a sonogram now."

Appearing on the podcast, he admitted he wrote that before their twins were born, and joked now he is "drowning in children".

On a more serious note, he insisted that people need to start being more open about miscarriages.

He said: "That sort of loss is really common, and we should - I don't know if talking about it alone is what we need.

"We at least need to start by talking about it more. And, of course, just to be clear, I'm speaking about miscarriages.

"They do happen all the time, and they can be really, really painful. Well, I would say they universally are painful. Maybe not everybody's fully allowed to feel that way."