ABC News' Felicia Patinkin and Amy Robach report:

It's one of the hottest and best-selling book series of all time. It has made millions of readers swoon and gotten A-list actors to throw their names into the ring, hoping to star in the big screen adaptation.

The erotic trilogy " Fifty Shades of Grey," "Fifty Shades Darker," and "Fifty Shades Freed," by British author E L James has sold 20 million copies in the last four months alone.

The books' contents - the relationship between protagonists Christian Grey and Anastasia Steele and their very explicitly detailed sadomasochistic sexual encounters - are so naughty they make grown men and women blush - at least in public. Elsewhere, they are said to have sparked a " mommy porn" revolution.

The revolution has been whispered about among friends and spilled out online on discussion boards like those of the popular pregnancy and parenting website BabyCenter.com.

"It was kind of erotic and sensual and loving and compassionate all at the same time, which kind of got my insides going, I guess," one user wrote.

Now the revolution is coming to the delivery room, where a baby boom sparked by the "Fifty Shades of Grey" phenomenon is predicted.

"Reading '50 Shades of Grey' is acting like an aphrodisiac for women," Linda Murray, Global Editor in Chief of BabyCenter.com, told " Good Morning America." "It's putting them in the mood more frequently and they're having more sex and they're ultimately getting pregnant faster."

While the "50 Shades" baby boom theory will only be proven months - nine, to be exact - from now, "GMA" spoke with a trio of couples to see if a book really could start a new population burst.

Carly and Leroy Gibson of Spokane, Wash., said 14 months spent trying to have another baby had taken the sexy out of sex.

"I think the fun was taken out of it at that point in time because you're like, 'Okay, here it is. Day 14. We've got five days to go. Go strong. I don't care if you're tired…it's time to go to work,'" Carly said.

After Carly began reading "50 Shades," Leroy says he noticed a change in his wife.

"She just put down the book and she was all over me," he told "GMA." "It was nice and enjoyable."

For Scott and Danielle Olszewski of New York City, getting pregnant with a third child was proving difficult after they'd had their first two kids with relative ease.

"I'm blessed that I have two healthy kids but I wanted that one more and I was sad," Danielle said. "Then Christian Grey entered my life."

A third couple, Michelle and Michael Burdick of Brockton, Mass., suffered a miscarriage and various health problems that made it difficult to add to their family of four. Then, a girlfriend of Michelle's recommended the "50 Shades" series.

"I started telling him [Michael] about it, bits and pieces, here and there," Michelle said. "Then I started taking pictures of the book and sending them to him."

"I opened up the email and I go, 'Okay, umm, are you suggesting something?,'" Michael said of his response.

The results for all three couples?

The Gibsons are due February 15. Michelle and Michael are due February 20 and Scott and Danielle Olszewski are due February 1.

If those dates clustered so close to each other in February raise suspicions, that would be correct. February is nine months after the "50 Shades" trilogy saw its biggest spike in sales this past May.

At least one of the couples may also be at the forefront of another possible trend, naming the "50 Shades" baby boom babies after the books' lead characters.

"I would like to name the baby Anastasia if it's a girl," Carly said, referring to the series' main female character. "He's not so much for the idea yet," she said, referring to her husband.