In their new book, “The Milk Memos: How Real Moms Learned to Mix Business with Babies—and How You Can, Too” (Tarcher/Penguin), Cate Colburn-Smith, 41, and Andrea Serrette, 36, share some secrets to success. (They’re finished nursing now. Cate’s daughters are 5 and 3, and Andrea’s son is 4.) NEWSWEEK’S Karen Springen talks with them about how they managed to work at IBM and keep nursing. Excerpts:

NEWSWEEK: Cate, Tell us about your experience using the IBM lactation room, a small janitor’s closet inside the women’s restroom that you called the Pumping Palace. Did you get the idea for this book on the spot? Cate Colburn-Smith: My first day back, I was all alone in that room. I wrote a note on a paper towel, “I’m a new mom. This is my first day back. Is anyone else using this room?” We replaced the paper towel with a series of notebooks with tips and facts about practical breastfeeding information, how to boost supply and all that. I got the idea that it would be a great basis for a book that other moms could benefit from. Andrea Serrette: when I joined the room several months later, I was feeling overwhelmed and exhausted. I started paging through the notebooks that were on the table. I felt a sense of relief that other moms felt the way I was feeling. I immediately thought it would be wonderful to turn these notebooks into a book and help moms feel supported.

Stay-at-home moms nurse longer than working moms. Is the solution less expensive breast pumps, longer maternity leaves or what? Andrea: It’s a combination of all of those things. We would love to see legislation that gives tax breaks to companies that allow a woman to pump at work, and longer maternity leave is also desirable. Cate: There are different fronts. One would be legislation at the federal and state level that businesses provide the time, support and space. A second front is that employers need to take it upon themselves to implement these family-friendly and breastfeeding friendly programs, recognizing how it benefits them through retention, loyalty, improved productivity, improved morale, lower healthcare costs. Mothers are absent less when babies are sick less often. And each woman needs to ask for what she needs.

What about nursing moms working at fast-food restaurants who use a bathroom stall—not even a janitor’s closet? Andrea: We were fortunate to at least have somewhere to go that was private. We talked to several moms who did pump on an open toilet seat. These are the moms who got the most creative—maybe going to their parked car or driving to find a place to pump. Cate: Our hearts go out to those moms who are dedicated enough to pump in a bathroom stall.

You have a chapter called “Indecent Exposure,” which tells the story of a Milk Mama who was pumping in her office when two maintenance men showed up to do a security alarm. Do you recommend putting up a sign to let co-workers know you’re out of commission? Andrea: We had moms here who did that. If they didn’t walk down to the lactation room, they put up a sign that said, “please don’t disturb.”

What did you tell co-workers when it was time to pump? Cate: In most cases, I would say I need to go do something important for 15 minutes, and I’ll be right back.

A daycare center in Ohio told one working mom, Robin Neorr, that she would need to pay $50 extra a week to keep her breastmilk in the refrigerator—which they then labeled “biohazard.” Did you use daycare and experience anything similar? Andrea: I did use daycare and did not have any similar experiences. I definitely was able to leave milk with the provider with no problem. Choosing a daycare provider is one of the hardest questions you have to make. Ask, “I’m a breastfeeding mom, not only will you feed this to my baby, but do you know the proper ways to store it? What will you do if you run out? Will you immediately give formula, or will you call me at work to see if I can come nurse my baby.”

In your epilogue, you say that you never expected that by the time your babies were toddlers, you’d feel nostalgic about pumping milk. Why? Andrea: For me, when I began the whole breastfeeding experience, I was not in love with it. In the end, I was. It was such a nice time to hold him and snuggle him and know that I was providing this nutrition for him when I got home. It allowed me to stay connected to him that way. When I got home, I’d actually be able to hold him and breastfeed him. It was a very tender time.

Cate: It was an opportunity for me twice a day to step out of my role as career woman on the fast track, at the time, to be a mom. Take a break from all the rushing and e-mails and phone calls. I sort of missed that when I no longer had the need to do that twice a day.

Anything else nursing and working moms should know? Andrea: It really is about keeping the guilt about going back to work at bay. There’s always someone out there to offer you an opinion about why what you’re doing is not the right way. Guilt about supplementing with formula, guilt about the kind of child care you pick. Just try to keep that at bay. Find the support of other moms. We did it and so can you.