Mandy Moore reveals the sentimental meaning behind son August's name

Mandy Moore is taking on a new role: Motherhood.

The "This Is Us" actress and her musician husband Taylor Goldsmith revealed they welcomed baby boy "Gus" in an Instagram announcement Tuesday.

"Gus is here 💙💙💙💙. Our sweet boy, August Harrison Goldsmith," Moore captioned the post. "He was punctual and arrived right on his due date, much to the delight of his parents. We were prepared to fall in love in all sorts of brand new ways, but it goes beyond anything we could have ever imagined."

Moore explained on Wednesday that August signifies the month that she and Goldsmith, who was also born in August, "found out we were having a boy."

"We always loved the name… so it was settled very early on in our book," Moore captioned an Instagram picture of a gray blanket embroidered with her son's moniker.

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Moore also shared the sentimental meaning behind the baby blanket that she "can’t wait to pass… on to our sweet August one day."

"For our anniversary in November, T gifted me with this blanket with the 'A' (for Amanda) made from extra material from my wedding dress," wrote Moore, whose full name is Amanda Leigh Moore. The blanket also featured "a 'T' (for Taylor) from his wedding shirt."

She added, "Felt like a very fitting amalgamation of our whole story."

Moore, 36, announced her pregnancy on Instagram back in September, posting a picture of Goldsmith caressing her growing baby bump. She wrote, "Baby Boy Goldsmith coming early 2021."

The actress posted regular updates since then, including an Instagram Story in early February about a medical condition that was complicating her pregnancy.

"Weekly platelet check at the hematologist," Moore wrote. "My platelets have dropped exponentially during pregnancy and it's sadly altered my birth 'plan.' Any other pregnant folks in the same boat??"

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In a January interview with Romper, Moore talked about her struggles becoming pregnant. Eventually she consulted a fertility specialist who suspected endometriosis.

“We did ovulation tests, all that stuff," she said. “I was fully prepared to go have surgery and fix my uterus and hopefully get rid of the endometriosis, if it was there. It was nice to have a plan and to know, OK, well, this is why I haven’t been pregnant yet.”

She wound up becoming pregnant shortly before she was set to undergo surgery.

Moore tied the knot with Goldsmith, lead singer of the folk-rock band Dawes, on Nov. 18, 2018, and wore a whimsical pink wedding dress.

"A year ago I married my favorite person in the world and I still pinch myself over whatever magic brought us into each other’s lives. You continue to set the bar high for the rest of the world (as a partner, brother, son, bandmate, friend, etc)," Moore wrote on Instagram in celebration of their first anniversary in 2019.

Moore, in her Romper interview, said Goldsmith is a natural dad.

“I think he’s been suited to be a father pretty much his whole life,” she said. “He’s been gearing up for this. Like in the morning, it’s funny, I’ll reach for my phone and he’ll reach right for whatever baby book he’s reading.”

Contributing: Cydney Henderson, USA TODAY

This article originally appeared on USA TODAY: Mandy Moore reveals meaning behind son's name