Why Mandy Moore Wearing 4 Types of Boobs in ‘This Is Us’ Speaks So Much About Pregnancy

This past season on This Is Us, Mandy Moore has blown us away with her relatable portrayal of Rebecca Pearson, a woman trying her best to balance raising triplets while keeping her dreams of a music career alive. But there’s a lot more that goes on behind the scenes to help Moore’s performance than you might realize: At the nineteenth Costume Designers Guild Awards (presented by Lacoste), Mandy Moore revealed some surprising details about how she gets into character to play Rebecca.

When Moore started filming the This Is Us pilot a year ago, she had to quickly adapt to wearing the “really epic prosthetic stomach and boobs” that costume designer Hala Bahmet gave her because Rebecca was pregnant with triplets. But here’s the real kicker: Initially, the breasts were made out of birdseed. (?!) “Of course,” Moore joked. “But Hala eventually adapted them into the most realistic boobs I’ve ever seen.”

And Bahmet didn’t stop there: She created multiple pairs that would more accurately reflect the changes a woman’s body goes through during a pregnancy. “There were four different pairs as I progressed through different stages of pregnancy,” Moore said. “Hala became the boob guru!”

It’s not just the prosthetics that make Rebecca Person feel so real, though. “On our show, [Rebecca] jumps through multiple decades and [Bahmet’s] costumes never distract,” Moore explained. “They always enroll just the right amount of nostalgia helping to create that immediate sense of familiarity that everybody gets when they watch the show.”

And it turns out there’s an upside to having a costume designer create everything from scratch. “Hala created the most meticulously beautiful, flowy, bohemian maternity dresses [for Rebecca],” Moore revealed, “only to have them completely tossed aside at the last minute because the directors wanted me in a white T-shirt and jeans.” Still, not all hope is lost. Moore had one last request before she left the stage: “Hala, I hope you saved them because I’m going to track them down and use them one day in real life!”

For more from last night’s show—which included guests like Meryl Streep (recipient of the Distinguished Collaborator Award), Lily Collins (Lacoste Spotlight Award winner), and Jane Fonda—watch our behind-the-scenes Snapchat video, below:

Related: The Reason Why Rebecca Didn’t Want Kids on This Is Us Is So Relatable