A set of premature twins and a 17-month-old son led Denise Stern to her latest business venture, an overnight service for over-worked, over-tired parents.

Stern, who lives in Haymarket, started Let Mommy Sleep — a company that provides nighttime care for newborns — four years ago. Since then, it has become a $750,000 business with 30 nurses.

In January, the company plans to begin franchising throughout the country.

“We’ve been growing to the point where I just can’t maintain it anymore,” Stern said. “I had to make a decision: Do we just continue to hire more and more nurses? Or do we find a way to spread out around the country?”

She chose the latter, and has so far invested about $75,000 to get the franchise off the ground. Stern plans to start locally, selling territories in Baltimore and Richmond before expanding to the rest of the country.

The biggest challenge, she said, will be convincing parents that it’s okay to ask for help.

“There’s this perception out there that this is a rich-lady luxury for people who don’t feel like getting up with their babies,” the 39-year-old said. “To this day, every single parent still apologizes for needing this service.”

The model has worked well in the Washington area, where many young professionals live far away from their families and have demanding jobs. But, Stern said, it may not translate to other parts of the country.

“I don’t want to generalize, but in rural areas or the Midwest, I think we’re likely to see more close-knit families,” Stern said. “The community ends up rallying around new mothers.”

Stern, who used to own Occoquan Basket Co., founded the business in 2009. She secured a $25,000 Small Business Administration loan, gathered a trio of nurses and set up a Web site and phone line.

The response, she said, was overwhelming. Since then, the company has grown steadily.

“Nobody comes in saying, ‘Okay, I’m going to use this service for two months,’” Stern said. “They start with one night, and one night turns into one week, turns into three weeks. That’s where most of our growth has been.”

More often than not, parents who call are juggling unforeseen circumstances: a sick child, a recovering mother or elderly parents in need of care.

Hourly rates range between $30 and $40, and there is an eight-hour minimum.

Arianna Zukerman, an opera singer who lives in Alexandria, used the service for the first six weeks after her daughter was born in 2011. The company’s nurses taught Zukerman and her husband how to feed their daughter and guided them through her first bath.

“When you’re a new parent, you don’t even know what a hungry baby looks like, especially at 3 in the morning,” Zuckerman said. “They helped me with all of that.”

Stern, who runs Let Mommy Sleep from a home office, says the bulk of her work takes place around 10 p.m., when nurses typically report to work. There is another round of phone calls at 6 a.m. as shifts come to an end.

So when does the mother of three sleep?

“Well,” she said, “I may be the owner of the world’s most ironically named business. Sleep is a luxury I’ll save for later.”