When Christina Applegate first met “Up All Night” creator Emily Spivey, they didn’t talk much about Spivey’s life.

One would think the conversation would have come up, considering the show was loosely based on Spivey’s experience as a working mother while at “Saturday Night Live.” Instead, Spivey was interested in Applegate, who had just become a mom herself.

“The week we shot the pilot was the hardest week I’d ever had. It was the first time leaving my daughter’s side,” Applegate recalls. “I had to balance rushing home with not wanting to come in early because I wanted to wake up with her; plus, the lack of sleep. After 10 days shooting the pilot, I really got it.”

The timing was happenstance, but Applegate demonstrated an uncanny ease settling into the skin of Reagan Brinkley. Her character similarly finds herself between two worlds: one as producer of the morning talkshow “Ava,” the other as the breadwinner for her newborn daughter, Amy, and out-of-work husband, Chris (Will Arnett).

“There are these households with stay-at-home dads and working moms, and exploring that is modern,” Applegate says. “It’s not something we’ve seen.”

That dynamic was appealing to Applegate, as was the show’s ability to turn its initial premise — the plight of new parents — into something universal.

“The show became about three friends, not just a baby,” she says. “(The advertising) might have scared people off.”

“Up All Night” has been picked up for a second season and Applegate believes the rapport among herself and co-stars Arnett and Maya Rudolph is the key to the show’s amicable charm. And she feels there’s no reason why laffs can’t be drawn from the good times as parents, not the disastrous moments.

“Comedy doesn’t have to come out of a heated argument,” she says. “These are the kinds of people who give each other a high five for completing the baby’s bath together.”