When reality TV first came calling, Bill Klein and fiancee Jen Arnold just said no.

“The producers approached us to do a wedding show,” Klein said, after seeing energetic Dr. Jen featured on “Good Morning America” for her work as a Stony Brook University Medical Center neonatologist. “But we just didn’t have the time to dedicate to doing a television show while coordinating a wedding. We didn’t really feel like it was the right move for us. So we turned them down.”

But “docu-soap” producers knew a telegenic modern couple when they saw one. Jen was moving to a new job at prestigious Houston Children’s Hospital. Bill would start working long-distance for his Emerge sales consulting firm. The two would be designing a new house and planning a family.

So the producers came back with a different idea. “And after mulling around the potential,” Klein said, “we decided to move forward.”

That’s how Bill and Jen became the next stars in cable TV’s latest unscripted trend — daily life ride-alongs with little people.

Their hit series, “The Little Couple,” now shooting its third season for a June return, is just one of four shows with which TLC has been cornering the market on docu-soaps built around people 4 feet tall.

Trendsetting fifth-season family smash “Little People, Big World” starts new episodes Monday. Other TLC projects spotlight the title Utah couple of “Little Chocolatiers” (premiering at 10 tonight) and Ohio parents raising an average-size baby in “Our Little Life” (which moves to Discovery Health tonight at 9).

Animal Planet is also in the mix, having just renewed January arrival “Pit Boss” (Mondays 9-11 p.m.), about short-statured inner-city L.A. tough guy and pit bull rescuer Shorty Rogers.

Even MTV seems interested. RealityWanted.com currently has a casting notice seeking “little people for stunts on MTV game show ‘Silent Library.’”

Which is likely not the kind of portrayal that persuaded “Little People, Big World” star Amy Roloff to invite TLC cameras onto the family’s Oregon pumpkin farm, from which she, her husband, Matt, and their four kids have become global stars.

Roloff says she wanted viewers to see “a regular family that faces challenges and that happens to have dwarfism and happens to be considered as having disabilities,” she said by phone. “We learn a lot about ourselves through this whole process, and we normalize dwarfism.”

“Little People, Big World” took viewers outside Portland to the Roloffs’ pumpkin farm, which hosts fall-season outdoor activities. Initially seen as a financial struggle to maintain, the farm grew into a tourist attraction as their TLC show became a hit. Viewers have followed the family through all kinds of ordinary activities — soccer games, house renovations, first dates, vacation travel. There also was Matt’s 2007 trial for drunken driving (the judge ruled him not guilty), and a serious accident with a pumpkin catapult, which resulted in hospital stays for son Jacob and adult family friend Mike Detjen. (His heart-related death two years later provided more drama.)

But from the start, “Little People” revealed the challenges of the Roloffs’ dwarfism — reactions to their size in public, physical obstacles they encounter, the family’s visits to Little People of America gatherings and dwarf athletic competitions.

TV hadn’t exactly portrayed dwarfs quite so naturally in the years leading up to the Roloffs’ debut. There was Jason Acuna as Wee-Man on MTV’s crude stunt show “Jackass,” and the Fox dating spectacle “The Littlest Groom,” which landed on Time magazine’s list of Top 10 Skanky Reality Shows. And it wasn’t as if scripted TV had done all that much better.

“The only person of short stature popular when I was a kid,” said Klein, “was on ‘Fantasy Island’ (Herve Villechaize’s island helper Tattoo), and I don’t even know if there was a point to that character.”

He has clear admiration for the Roloffs. “They’ve done a lot for us (little people) as individuals,” he said by phone. “Seeing them in mainstream society breaks down a barrier. You see they’re just average individuals, trying to make it in a world that isn’t easy, regardless of stature.”

‘Little People, Big World’

When: 8 p.m. Mondays

Where: TLC

‘The Little Couple’

When: 9 Tuesdays

Where: TLC

‘Little Chocolatiers’

When: 10 Tuesdays

Where: TLC

‘Pit Boss’

When: 9 p.m. Mondays

Where: Animal Planet

‘Our Little Life’

When: 9 Tuesdays

Where: Discovery Health