Source: Jayme Deerwester via usatoday.com Four female flight attendants who work for Frontier Airlines are suing the carrier, alleging it discriminated against expecting and new moms by mandating they go on maternity leave early – at times prompting them to use up their paid leave before they give birth. The lawsuit also accuses the airline of making it difficult for them to breastfeed or pump, stating the airline goes so far as to prohibit female pilots and flight attendants from pumping while on duty. They say the Denver-based airline's policies violate Title VII of the Civil Rights Act and the Family Medical Leave Act as well as Colorado laws that protect pregnant and nursing mothers from discrimination. Their federal suit, filed Tuesday in the U.S. District Court of Colorado, says the women "faced discipline for absences related to pregnancy and were eventually forced onto unpaid leave weeks or months before their due dates with no alternatives, depriving them of critical income when they needed it the most. With no paid parental leave and only the short unpaid leave required by federal law under the Family and Medical Leave Act (“FMLA”) – if any remained to them." While it's understood that pregnant flight crew members cannot fly later in their pregnancies, particularly during their third trimester, the plaintiffs allege Frontier ignored or denied their requests for temporary ground assignments so they could continue working while unable to fly. They say they were left with no alternative but to take leave. It goes on to allege the airline has accommodated flight attendants' requests for ground assignments based on other medical conditions but not for pregnancy or postpartum reasons. One of the plaintiffs, Renee Schwartzkopf, says that because Frontier would not allow her to modify her schedule to allow time to pump breastmilk, she was reduced to doing so in an unsanitary aircraft lavatory. Fellow plaintiff Heather Crowe says the airline denied her request to shift to a temporary ground assignment so she could breastfeed. Frontier spokesman Zach Kramer told USA TODAY the airline "has strong policies in place in support of pregnant and lactating mothers and remains committed to treating all of its team members equally and fairly. Frontier offers a number of accommodations for pregnant and lactating pilots and flight attendants within the bounds of protecting public safety, which is always our top priority. Frontier denies the allegations and will defend vigorously against these lawsuits." Get the Travel newsletter in your inbox. Travel industry news and expert reviews on air travel, hotels, cruises, and more. The complaint argues, "Frontier has systematically discriminated against pregnant and breastfeeding flight attendants by penalizing them for pregnancy-related absences protected under the FMLA, singling out pregnancy and breastfeeding for worse treatment than other conditions, and failing to comply with Colorado laws that require employers to accommodate pregnancy and related medical conditions and specifically mandate the provision of break time and a private, sanitary location to pump." "Frontier’s policies and practices challenged here are a legacy of the long and unfortunate history of sex discrimination in the airline industry as a whole. Most airlines at one time had explicit policies forcing female flight attendants off the job when they got married or became pregnant," the suit alleged. "Although many of these more overt practices have been abandoned in the face of lawsuits and public outcry, more subtle forms of discrimination persist, many of which have the same effect of forcing women off the job, especially when they become pregnant or have children." In addition to unspecified compensatory and punitive damages, the women seek to have Frontier legally barred from enforcing their current policies and required to adopt new ones that make "reasonable and effective accommodations for pregnant and breastfeeding flight attendants" as well as better training for managers and human resources personnel regarding the new policies.