Hugh Hefner's son Cooper Hefner welcomes first child with Harry Potter actress Scarlett Byrne

Cooper and Scarlett Hefner have named their baby girl after Cooper's grandmother. Photo / Getty Images

Hugh Hefner's son Cooper Hefner has welcomed his first child with his wife Scarlett Byrne.

The 28-year-old son of the late Playboy founder became a dad to a baby girl named Betsy Rose Hefner, who is named after his late grandmother, Betsy Aldridge-Conrad, who passed away last month.

Cooper told E! News that their little bundle arrived on Monday at 5.23pm and weighed in at 6 pounds, 5 ounces.

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At 5:23pm this afternoon Scarlett and I welcomed our daughter Betsy Rose Hefner into the world. We are overwhelmed with gratitude, love and joy.

A post shared by Cooper Hefner (@cooperhefner) on Aug 24, 2020 at 8:15pm PDT

The businessman gushed to the news outlet: "We are overwhelmed with joy to share that our daughter, Betsy Rose Hefner, has arrived.

"We look forward to being home and spending time together as a family in the days and weeks ahead."

On the inspiration behind their little one's moniker, he added: "My grandmother meant the world to both Scarlett and I."

Hugh Hefner with his wife, model and actress Kimberley Conrad, and their two sons, Marston and Cooper. Photo / Getty Images

The couple announced their pregnancy back in March.

Alongside a snap of Scarlett proudly displaying her bump, Cooper wrote on Instagram: "Scarlett and I have been blessed with wonderful news we are ecstatic to share. This summer we will be welcoming a new member to the family.

"The two of us could not be happier as we wait for the arrival of our little one."
The brith of their daughter comes months after the couple tied the knot after being engaged since 2015.

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Cooper and I are excited to share that we legally married. We are looking forward to planning our wedding in the coming months where we will celebrate further with our friends and family. I love you Cooper. I am proud to stand by your side, as your partner, your friend, and your wife. I cannot wait to continue building a life together. My heart is so full and I am so grateful for our love.

A post shared by Scarlett Hefner (@scarletthefner) on Nov 4, 2019 at 11:35am PST

Posting on Twitter in November, Cooper wrote: "Scarlett and I have made it officially legal and the two of us could not be happier. Cheers to a life full of love, happiness, adventure, and great purpose, Mrs. Hefner. I very much look forward to planning our wedding celebrations in the months ahead. I love you, Scarlett."

British actress Scarlett, 29, also confirmed the news on Instagram, where she changed her name to Mrs. Hefner.

The 'Harry Potter' star wrote: "Cooper and I are excited to share that we legally married. We are looking forward to planning our wedding in the coming months where we will celebrate further with our friends and family."

"I love you Cooper. I am proud to stand by your side, as your partner, your friend, and your wife. I cannot wait to continue building a life together. My heart is so full and I am so grateful for our love."