John Legend and his wife, Chrissy Teigen, have been married for 4 years, and the “Ordinary People” musician says he feels closer than ever to his wife.

During an interview with Cosmopolitan, the Grammy Award-winning musician detailed how in vitro fertilization (IVF) brought him closer to his wife.

“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,” Legend explained when ask about trying for another child.

The couple welcomed their 16-month-old daughter Luna, who was conceived with the help of IVF.

“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,” said Legend. “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. 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.”

Despite their challenges, Legend told the publication that Chrissy’s joy is one of his biggest priorities.

“I want her to be happy and to live the fullest, most awesome life she can, and I want us to do it together.”