Mandy Moore relied heavily on Hilary Duff during the "scary" period that marked her first pregnancy.

As the pair navigated motherhood together during the Covid pandemic, the 42-year-old This Is Us star said her bond with Hilary, 38, grew massively.

During an upcoming appearance on Amanda Hirsch's Not Skinny But Not Fat podcast. Mandy, who shares sons August 'Gus', five, and Oscar 'Ozzie', three, as well as 21-month-old daughter Louise 'Lou', said Hilary became an invaluable source of support as she prepared to become a mother for the first time.

Mandy said: "We went through - (Hilary) went through her third pregnancy, and I went through my first pregnancy - like together. And so, like I really was able to immediately lean on her."

According to a clip from Mandy's podcast appearance, obtained by PEOPLE ahead of the episode's release, Mandy also reflected on how Hilary welcomed a group of new mothers into her circle during a period marked by lockdowns, restrictions and uncertainty.

Mandy added: "(Hilary) was the one that welcomed in all these other new moms during the pandemic to a baby class at her house."

She continued: "We started with like baby music class when our kids were like little blobs just lying on the grass. It was so much fun."

Hilary, a mother of four, organised classes and gatherings that helped create a support network among parents during the pandemic, Mandy explained.

Mandy said: "I have become a mom with her and she's the best."

The actress also reflected on the wider circumstances surrounding their pregnancies, describing the uncertainty many parents experienced during the height of Covid restrictions.

She said: "It was feeling incredibly confusing and scary to be like pregnant during that strange time that gave us all PTSD."

The friendship between Mandy and Hilary dates back several years.

Speaking to Glamour in February for a cover story focused on Hilary, Mandy discussed how their relationship developed following a chance meeting in 2018.

Mandy said: "I feel exceedingly lucky that my kids happen to spend time with people that I feel like our values are aligned with."

She added: "The friends that I've made since becoming a parent are some of the deeper, more surprising friendships I've found as an adult."

The podcast conversation comes as Mandy continues to be associated with her acclaimed role as Rebecca Pearson in This Is Us, while Hilary remains best known for starring in Disney Channel hit Lizzie McGuire, as well as leading TV Land comedy Younger and releasing chart-successful pop music including Come Clean and So Yesterday.

Mandy first rose to fame as a singer with hits including Candy before establishing herself as an actress in projects such as A Walk to Remember, Tangled and the Emmy-winning drama This Is Us.

Hilary became a household name through Lizzie McGuire, later starring in Younger and maintaining a successful music career alongside her television work.