Pregnancy author Heidi Murkoff on grandchildren

Heidi Murkoff (right) with her expectant daughter, Emma Bing.
CBS News

(CBS News) The book "What to Expect When You're Expecting" has been on the bedside table of many a mother-to-be, including a very recent mother-to-be who years ago played an indispensable role in making the book the success it is. Tracy Smith has a story that spans the generations:

Lying on her back in Dr. Howard Mandell's Beverly Hills exam room, first-time mother Emma Bing is, well, a bit nervous.

Happily, her mom, Heidi Murkoff, is at her side helping her get through it all.

"I love having Heidi Murkoff in the room," said Dr. Mandell. "Every doctor likes to be on their toes."

You might not know her face, but chances are she helped you through your pregnancy, too.

In 1982 Heidi Eisenberg was a young writer who unexpectedly found herself in a family way.

"I did not see that coming," she said. "Completely unprepared, totally clueless. I had hundreds of questions."

And she had a tough time finding answers. At that time there were very few pregnancy manuals available. "There were doctor ones, which were kind of, like, 'Don't worry, honey, we'll take it from here" kind of thing," Murkoff said.

"So reading those pregnancy books at the time, you thought your fetus was doomed?" asked Smith.

"Yeah, actually, I did," Murkoff said. "I'd had a couple of drinks, a couple of times a week . . . I find out I'm six weeks pregnant, and then I pick up a book that says, you know, alcohol is poison. You know, so clearly, I felt I had a lot to worry about. And worry, I did!"

Cover of the fourth edition of "What to Expect When You're Expecting" by Heidi Murkoff and Sharon Mazel. Workman Publishing

So she did her own research. And with some help from her mom, started writing. Shortly after Heidi had little Emma, she delivered her first book: "What to Expect When You're Expecting."

She said initially he response wasn't good: "None of the major bookstores carried the book. The feeling was, you know, the couple of pregnancy books on the market, that was plenty. We didn't need more, that was enough."

But among pregnant women, word of the book got around, and in a few years it became a must-read for anyone in a maternity top. Tracy Smith said when she carried her twins, she kept a copy handy.

And she was hardly alone. It's been estimated that 93 percent of all women who have ever picked up a pregnancy book have read "What to Expect."

And according to the latest numbers out this morning, "What to Expect When You're Expecting" has been on The New York Times bestseller list for 600 weeks.

It all makes Emma breathe easier, sort of.

Smith asked, is she less freaked out because of who her mom is? "I think so," Bing said, adding, "I'm pretty freaked."

Worried moms can get a question answered online, 24/7, often by Heidi Murkoff herself.

Online and off, the discussion has always been frank, and for some women frankly frightening.

"What about this idea that it scares women? Why are there some doctors who say, 'Don't read it'? asked Smith.

"I do think that they're speaking to older editions of the book," said Murkoff. "The thing is, it's a fine line between the right amount of information, and you know, TMI, 'too much information.' I'm always walking that line.

"Knowledge is power -- especially empowering when you're pregnant," Murkoff said.