But the focus on maternity leave gives the impression that if only America had a reasonable policy, women would be able to participate fully and equally in the workforce, they’d climb the ranks of management, and there would be more female senators. Our interviews revealed that while working parents would welcome improved paid parental leave, it’s only the tip of a very large iceberg: The real challenge is everything that comes after those hazy newborn days.

For 70 percent of our sorority-mates, their maternity leave was barely worth mentioning. They had their babies, took leave, and came back to work with a breast pump in hand. All continued with the jobs they’d had before becoming mothers. But over time, they began to either drop out or scale back, overwhelmed by competing desires to be present parents and hard-driving workers. And today, 17 years after the first of our classmates began having children, only eight parents (32 percent of the group) have continued with their original career trajectories.

So why did these women retreat from the workforce? Our interviewees were hit hard by a combination of factors that created an impossible childcare situation.

For starters, the basic structure of what work looks like hasn’t changed since Charles Lamb documented his typical workday as a clerk at the East India House in 1792. Yes, more companies offer flexible hours and allow remote work, but the bulk of the work world still relies on in-person face time. In particular, a number of our interviewees with finance or client-related jobs spoke about the need to be physically in the office. And as anyone who has been in an office lately knows, most professionals no longer end their weeks at the 40-hour mark. Today people work an average of 8.6 more hours in 2010 than they did in 1979, according to a 2012 study from the Economic Policy Institute. By definition, when a worker is in the office eight or more hours a day, in addition to a commute, that is time spent not caring for children or the household. Which is to say: For the working world to continue to function as it does, and for houses and children to continue to function as they do, someone must take on double duty.

What we heard from our former college classmates is that the double duty often falls to them, which means that women are the ones trying to cram the most into their days. When a client needs to be seen in person, necessitating a long commute and lots of extra hours in the office, women suffer. A wealth of research backs this up. A 2007 University of Chicago study found that cities with longer commutes have fewer married women in the workplace, and according to a 2009 study from the University of Sheffield, women find commuting more psychologically taxing than men do, in part because they spend their commutes thinking about all of the things they need to do when they get home to make the household run smoothly. Men, the study found, spend their commutes relaxing or listening to music.

A second complicating factor is the geographic mobility of our interviewees. The 2010 U.S. census found that 53 percent of working mothers rely on a grandparent to watch their preschoolers while they’re at work. But many of our former classmates’ jobs had taken them far from their families (which puts them in line with this 2012 study by Atlas Van Lines showing an increase nationwide in corporate relocation), and they had no one to call on in an emergency, never mind day-to-day childcare. As a result, many felt isolated when it came to childcare—and if they didn’t feel comfortable with daycare or a nanny, or couldn’t afford it, the obvious choice was to work less and parent more.

“We’ve never lived near any family, which would have been helpful as a working parent,” wrote a former school-district fundraiser, explaining why she’d left her job shortly after her daughter was born. Some of our subjects have gone to extremes to make their jobs work despite the lack of grandparents nearby. A partner at a management-consulting firm described how she’d flown her father from Ohio to Boston to babysit while she and her husband were both traveling for work. (On the plus side, he potty-trained her 3-year-old while there.) When her banking job forced her to relocate to Charlotte, North Carolina, with an infant, one woman convinced her parents to move with her, only for them to visit and then change their minds, insisting they’d confused the town with Charleston, South Carolina.

While moving far from home means you can’t call your mother to come watch a sick kid, and the work world continues to function as though there is some phantom third household partner buying groceries and shuttling children to pediatrician checkups, the final blow comes from perhaps an unexpected institution: school. The school day still ends at 3 p.m., or earlier, a holdover from the 19th century when students left their books behind and went to work on the family farm. Some schools offer after-school programs, but even these typically end at 5:45, as though everyone is still leaving work at 5 o’clock sharp and has an easy commute from work to school. As a result, what to do with children after school dismissal is an issue that looms large for our interviewees. And they’re not alone. A 2009 study by the Afterschool Alliance found that 15 million children are left home alone every day across the country, with some as young as 5 years old.

Not only does school end at an inconvenient time for working parents, but in an effort to be more transparent about what kids are learning and to feel more inclusive, schools now invite parents (often with minimal notice) into the classroom to participate in events on a regular basis. Between fundraising for schools with paltry budgets and attendance at school plays and birthday parties and sporting events and monthly parents-as-learning-partners programs, parents find themselves being asked to put in an appearance at school on a weekly basis. For working parents, this amounts to a lose-lose choice between work and parenting—either take a ridiculous amount of time off of work and risk getting fired, or leave your first grader in tears because she’s the only one whose parent didn’t show up to color with her.

Given the choices, it’s no wonder that 60 percent of the women we interviewed who went back to work decided to either scale back their careers or leave work altogether. Of the eight women who never strayed from their original career trajectory, five have partners who are the primary caregiver. That is, they are married to men who are either full-time stay-at-home fathers, or who have explicitly agreed to do the bulk of the childcare. All of which is to say: For our subjects, stingy maternity leave is not the problem. The problem is that kids continue to have needs beyond being nursed and put down for naps. And those needs require more, not less, parental presence over time.

A C-suite-adjacent executive at a large Chicago insurance company noted that she’s adjusted her schedule so she can spend more time with her middle-school-aged son. Her husband stays at home with the kids, but even so she realized that her son needed her to physically be around more. So now she has breakfast with him every morning, watches him board the school bus, and tries to be home in time to make dinner most nights.

But for some of our former classmates, the lack of access to childcare is a deal breaker. A former part-time management consultant in Washington, D.C., said that after her firm was acquired she was told she needed to revert to full time and was given five days to find childcare. “With no family near us and no financial absolute requirement for me to work, I left,” she explained. She’s been at home with her kids for the last 14 years. Her maternity leave was excellent.

Read the next piece in this series here.

Hana Schank is a design-research consultant. Her writing has appeared in The New York Times, The Atlantic, and The Washington Post.