The 37-year-old actress and 36-year-old actor attended a New York screening of "Una" after reportedly welcoming a daughter in August.
Prepon and Foster both wore casual ensembles, with the actress in a grey sweater and black pants and Foster in a black shirt and jeans. Prepon showed a smile and kept Foster close as they posed for photos.
People reported Aug. 24 that Prepon had given birth to a daughter.
The couple have yet to confirm their child's name and sex, although Prepon did refer to the baby as a "she" in an interview in June.
"It's kind of weird, 'cause it sneaks up on you where you're like, 'I can't believe it's been eight months already,'" the actress said of her pregnancy on "Live! with Kelly and Ryan."
"But then you're like, 'Oh my God, she needs to like, come out already.'"
"But it's so wonderful," she gushed. "It's just like, a blessing. It's like, she likes it here. She's already kicking."
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Prepon and Foster got engaged in October 2016 after several months of dating.
The actress discussed her wedding plans in an interview with E! News in January, calling Foster "the love of [her] life."
"We want a really small wedding but we have a lot of people that we love and care about," she said.
"It's weird, [but] apparently doing the list for your wedding is a whole thing that could cause some issues."
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