R&B singer John Legend has opened up about his efforts to become a dad again, revealing he and model wife Chrissy Teigen are closer than ever as they try for a second child.

The stars welcomed daughter Luna last year (14Apr16) after secretly struggling to become parents and they have recently started trying to expand their family again using in-vitro fertility (IVF) treatments.

"Having a baby is a big challenge for a couple, and going through that together strengthens your bond, because if you make it through (having a child), you know you can make it through anything," John tells America's Cosmopolitan magazine. "I think it’s especially difficult when you can’t conceive naturally. You want to feel like everything’s working properly and want everything to be perfect, but sometimes it’s not."

The All of Me hitmaker has nothing but praise for those helping the couple achieve its family dream, and he is forever thankful to the pair's physician for giving him and Chrissy hope.

"I wouldn’t say we can’t conceive naturally, but I would say that it’s enough of a challenge where it felt like we needed help," he shares of their decision to turn to an IVF doctor. "We’re lucky that we’re living in an age where we can conceive in other ways. (IVF) brought us Luna and hopefully it will bring us a few more awesome kids too."

Chrissy sobered up ahead of her new battle to become a mum again, recently revealing she is curbing her alcohol consumption out of fear she was drinking too much - and John has nothing but support for his wife of four years.

"We’re always honest with each other, so we discuss everything that’s on our minds," he adds. "When she was thinking about how she wanted to drink less, we talked about it.

"I just want to support her. I want her to be happy and to live the fullest, most awesome life she can, and I want us to do it together. Whenever she sets her mind to anything, I always tell her, 'I want to support you and help you do it'."