Nicky Hilton and James Rothchild have added one to their brood.

“We are officially a party of 5! Welcome to the world sweet boy. Mom, dad, and big sisters could not be more smitten,” Hilton wrote on Instagram alongside a black and white picture of the pair.

The 38-year-old fashion designer is yet to reveal her newborn boy’s name and date of birth.

She had announced her pregnancy in late January and followed by a picture of herself cradling the baby bump in February. Hilton and Rothschild, 37, are also parents to daughter daughters Lily-Grace, 5, and Teddy, 4.

Kathy Hilton, a former actress, and Ricky Hilton, a businessman also shared the pregnancy news with their followers, “It’s our first grandson. I’m not speaking out of turn.”

Nicky also went on to share a video of her daughters alongside the words, “Feeling extra blessed this Mother’s Day. Our family is growing. So excited to meet our little one this summer.”