Although she enjoys nursing her 4½-month-old daughter and believes breastfeeding is best for her baby, K.M. fears she may soon have to stop.
Her employer has provided a separate pumping room, as federal law mandates, but K.M. said it's difficult for her to leave her desk during the work day to pump milk. K.M., who didn't want to divulge her real name or her employer's out of fear of reprisal, said she had a large case load and numerous meetings throughout the day and that she could use her time more efficiently by staying at her desk to pump. And that's what she tried to do.
"I was covered up and faced away from everyone, so my co-workers didn't mind, but after about a month, it came to my attention that somebody complained and HR asked me not to do it," she said.
Her employer, K.M. said, recently changed its policy and now prohibits pumping outside the designated area.
"I'm really at a crossroads now. Is this the universe telling me that I need to make a change? My priority is my family, but in order to make my family a priority, I need to work," she said.
Since cutting back to part-time work or leaving the work force entirely is not financially possible for K.M. or her family, the only option for her may be to stop breastfeeding altogether. K.M. still hopes to work something out with her employer that would allow her to continue to work full-time and still breastfeed, but so far, no compromise.
K.M. is just one of many mothers facing this dilemma: Quit breastfeeding, or face the economic consequences of lost income. While breastfeeding, unlike bottle-feeding, doesn't require a cash outlay for formula and bottles, a new study suggests that many nursing mothers pay a much bigger financial price in terms of lost income.
Evaluating a range of data from a U.S. national database, researchers found that while all first-time mothers lost income after giving birth, mothers who breastfed for six months or longer experienced a much bigger and lengthier loss of earnings compared to mothers who breastfed for shorter periods of time, or not at all.
"Studies say that one of the reasons women choose to breastfeed is because it's free, but is it really free? It takes time, and women's time is worth money," said co-author Mary Noonan, an associate professor of sociology at the University of Iowa in Iowa City.
One of the main reasons for the lost income, the authors said, is women often leave the work force entirely or scale back their hours, and one of the main reasons for that decision is many workplaces don't provide a supportive environment for nursing mothers. The law only applies to workplaces with more than 50 employees, the authors said, and even in cases when it does apply, many women still feel stigmatized.
"If it's not a supportive workplace and women choose to breastfeed for six months or longer, these women are more likely to leave their jobs if they have the means to do so," said Phyllis Rippeyoung, a co-author of the study and an assistant professor of sociology at Acadia University in Nova Scotia.
The authors take pains to emphasize that their study does not suggest that women should not breastfeed because of worry over balancing work and family responsibilties. Their message, Rippeyoung said, is that women should be made aware of the potential economic consequences of breastfeeding.
"There are these public health prescriptions that women are being told to breastfeed or otherwise they are going to harm their baby, but if she's going to be given these sorts of messages, she should be told to take into account earnings losses," she said.
The study also found that long-term breastfeeders were also more financially able to leave the work force. These women were more likely to be married to men who could provide support if their wives needed to leave the labor force.
Elizabeth Hoffmann, an associate professor of sociology at Purdue University in West Lafayette, Ind., has also conducted research on breastfeeding and the workplace. She found while talking to working mothers that long-term breastfeeders were also more likely to have jobs that allowed for flexibility and privacy for pumping milk, meaning they could continue working.
"Flexible schedules and private offices are critical for successful long-term breastfeeders," Hoffmann said. "If they don't have these privileges, it's hard for them to pump."
The study authors also said that despite the increasing numbers of mothers who breastfed, workplaces had not caught up with the demands of lactating women, even with the federal law in place.
The 2010 Patient Protection and Affordable Care Act requires that workplaces with more than 50 employees create a separate room that is not a bathroom for nursing mothers to pump, and also mandates that they receive two 30-minute breaks. But experts said that's not enough support for nursing mothers.
Not every breastfeeding woman works in a place with more than 50 employees, and the breaks are often unpaid, Noonan said.
And another problem with the law, said Philadelphia-area women's and civil rights attorney Jake Aryeh Marcus, is that no penalties are imposed on employers who don't comply unless a woman is fired.
"The women who have laws assisting them have state laws assisting them," she said.
There are 19 states with laws in place protecting breastfeeding women against discrimination at work. The law in another state, Montana, protects only public employees. Not all states have enforcement provisions in place, however.
"There has been some positive change," Marcus said. "There are some business that have voluntarily complied with the law without doing a more in-depth examination about whether they actually had to." Some of these businesses have done so, she said, to avoid having formal complaints lodged against them.
There is another proposed law -- the Breastfeeding Promotion Act -- that was introduced in both houses of Congress and is currently in the House Committee on Education and the Work Force. If eventually passed, this law, Marcus explained, would make breastfeeding discrimination akin to sex discrimination.
A study published in March found that many mothers felt pressured to breastfeed and felt guilty if they didn't.
"There are many competing demands on new parents: lack of sleep; crying, unsettled babies; other children to look after; and work commitments," lead author Dr. Pat Hoddinott at the University of Aberdeen in the United Kingdom told ABC News when her research was published. "Families very carefully weigh the long-term benefits of breastfeeding with the family's immediate well-being.
"It puts a lot of strain on new families," Hoddinott said. "Instead of stating the World Health Organization guidelines, we should be telling women to breastfeed as long as they can. There's accumulating evidence that breastfeeding for as long as possible has heath benefits for both mother and baby."
The Centers for Disease Control and Prevention recently found that only 13 percent of new mothers in the U.S. were breastfeeding exclusively at six months. Breastfeeding advocates consider six months to be the best option for infants' health, and said they'd been pushing for mothers to receive more support.
"When mothers can't' breastfeed, it is almost always because the supports were not in place for her to do it, and those supports come from society and the health care profession," Dr. Kathleen Marinelli, a pediatrician at Connecticut Children's Medical Center in Hartford, told ABC News in March.
Given her own difficulties in breastfeeding on the job, K.M. now understands firsthand why many mothers stop nursing.
"Employers need to realize that there are benefits for them as well as for mothers and babies," she said. "My baby will be healthier, and I will feel better and less stressed, and will ultimately need less time off."
ABC News' Karin Halperin contributed to this story.