Power Lunch? : They ate a salad. They went into labor. And another urban myth is born.

Pam Pepper wanted exactly what every pregnant, overdue woman wants--contractions, lots of them, so she could welcome her bundle of joy and finally see her toes again.

But there she was last October, two days after her due date, with nary a twinge. “I was feeling fat,� recalls the Sherman Oaks hair-salon owner, although she had gained only 23 pounds. She was discouraged, even though her husband, Michael Nahman, tried to be understanding. “There’s not much a husband can do in this situation,� he allows. “We did go for lots of walks.�

Her obstetrician clucked about the inexact science of predicting labor onset.

Looking for sympathy, Pepper called a friend, Nedra Klein, who offered a suggestion that at first sounded outlandish: She should try a salad at a Laurel Canyon restaurant that seemed to speed up Mother Nature. At least eight overdue women in the last year or so have credited the salad with sending them to the hospital when the standard advice--Think positive! Take a walk!--failed them.

Klein couldn’t vouch for the salad’s power. She had heard about it from her exercise teacher, who hadn’t tried it either.

But then, being overdue by even a couple days can make sensible, logical women consider possibilities they’d normally dismiss.

“Take me there for lunch!� Pepper begged Klein. “I’ll do anything.�

The next day, they met at Caioti, a funky pizza-pasta-salad restaurant at Laurel Canyon Boulevard and Kirkwood Drive. Inside, the rustic tables and dark, cool air make the atmosphere decidedly relaxed; a large aquarium with colorful fish separates two rows of tables.

Pizza with smoked chicken, artichoke hearts and seafood top Caioti’s menu--the brainchild of owner Ed LaDou, a former pizza chef at Spago who also helped develop the concept for California Pizza Kitchen.

But Pepper wanted only the salad. Klein was uncertain which salad contained the legendary ingredients. Their waiter had heard the folklore, but also was unsure. So Pepper and Klein ordered three salads the waiter thought were possibilities: Romaine and Watercress, Wild Mountain and Chopped Salad.

They picked at all three salads and then, feeling as if she’d done all she could, Pepper went home to relax. “About 5:40,� she recalls, “I was on the phone with a friend and had a bad cramp.� Soon after, her husband came home from work and they sped off to the hospital. After a 14-hour labor, Blake Pepper-Nahman, now 8 months old, arrived.

When Pepper told her obstetrician about the salads, he just laughed.

But Tina Ferraro, a Van Nuys romance novelist, didn’t laugh a bit when Pepper recounted the story. Pregnant with her third child, Ferraro knew Pepper from taking her two kids to Peppermints, the children’s hairstyling salon Pepper runs. Ferraro had a history of late deliveries and wasn’t eager to repeat.

By now, Pepper had learned from LaDou that the salad credited by some diners with labor-inducing properties is the Romaine and Watercress: a bed of lettuce topped with walnuts, Gorgonzola, watercress and a strong basil-balsamic vinaigrette.

On March 2, her due date, Ferraro went for a routine doctor visit. He guessed “it would be another week,� says Ferraro.

So about 1 p.m., she headed to Caioti for Romaine and Watercress Salad. “After the salad, that night he (the baby) started kicking like crazy,� she recalled over a recent lunch (of pizza) at the restaurant. Son Nicholas was born the next day.

The legend was growing.

Shelly Holmes’ doctor had predicted a Feb. 23 due date, then revised it to March 1. Soon after, her husband, Randy, a free-lance photographer, ran into Pepper at a neighborhood photo store as she picked up pictures of Blake. They struck up a conversation and when he confided that his wife was overdue, Pepper mentioned the salad.

Shelly Holmes was intrigued, but decided to wait it out. On March 7, though, the couple decided to swing by Caioti after church, she recalls: “We went for fun. We figured we’d have a good laugh.�

She tried both the Wild Mountain salad and the Romaine and Watercress. The contractions started about midnight. Christian was born March 8.

Owner LaDou is bemused by it all. “Whether it’s in the mind or in the salad, who knows?� he says. “Maybe it’s something in the watercress or the balsamic vinegar.�

That guess might not be far off the mark, two local obstetricians speculate.

“There is no science behind it, but there is a possible explanation,� says Dr. Raul Artal, a USC professor of obstetrics and gynecology and author of “Pregnancy and Exercise,� just published by Delacorte Press. “Certain plants have ergot alkaloid derivatives, substances that cause the uterus to contract.� Balsamic vinegar might contain these, he says.

The same possibility of ergots in the vinegar was voiced by Dr. Irwin Frankel, an obstetrician-gynecologist at Century City Hospital and USC clinical professor of obstetrics and gynecology. “Eight patients don’t make a clinical study,� he says, “but I’ve learned not to pooh-pooh things seemingly off the wall.�

Still, adds Dr. Donna Shoupe, USC associate professor of obstetrics and gynecology: “I wonder how many overdue pregnant women have eaten it (the salad) and not gone into labor.�

A UCLA chemist, who requested anonymity, said that although the vinegar theory sounds a little far-fetched, it is conceivable.

So should women less than nine months pregnant avoid the Romaine and Watercress Salad? Probably only if they are at risk of premature delivery, Frankel says. “The uterus contracts normally and spontaneously with intercourse and at other times,� he notes.

Pepper, meanwhile, continues to spread the word about the salad.

And LaDou quips that he might add an asterisk on the menu by the Romaine and Watercress Salad and insert a warning: Caution. Could be labor-inducing. Please wait until you are full term to order this salad.