You don't need to be a sociologist to notice that women tend to adjust their careers once kids come along, often looking to shift their schedules, locations or workloads when baby arrives.

But Stanford researcher Brooke Conroy Bass noticed something else: Women are shifting their career focus in advance of having kids, making professional calculations that impact opportunities down the line.

Here are the 5 things you need to know from Bass' study on how children impact men and women's careers—

1. Women make changes to their career trajectory based on the possibility that they may have kids in the future

They do this "just by imagining the additional responsibilities and care work that comes with parenthood," Bass explains. This can come in the form of choosing college majors and entry-level jobs in fields that they think can better accommodate future children. Or it can cause them to lean away from taking on more responsibility if they don't think it would lead them to a role that would allow them to balance life with kids.

"Women tended to downshift educational or professional opportunities as a result," even before having kids, Bass found.

2. Men don't plan for parenthood the same way

Bass' research indicates that while men actually take on more responsibility once baby arrives, they do not worry about how to balance work and life before having kids. This may result in women assuming that they are primarily responsibility for adjusting their careers, and that men are not.

3. "While most couples maintain a sense of egalitarianism before having children, many shift to more traditional roles upon the birth of the first child."

This is not necessarily a problem, if couples consciously choose these roles and are happy with them. Bass' research suggests both that men should be encouraged to be more aware of how parenthood might impact their careers, and that women should be thinking about how their choices before kids might impact employment opportunities later.

4. Women are qualified

Women are now earning the majority of college and graduate degrees in the United States.

A more highly educated female population means that gender dynamics are in flux in many families. As many women begin to out-earn their men [new research shows that Millennial women in their 20s are now earning more than men of their generation], the question of whose responsibility it is to keep the home fires burning is a very real, and evolving, one.

5. Bass research suggests that women might consider maximizing career potential before having kids

Just as men might consider how becoming a father could transform their careers.

Raising children is a team sport.

Bass suggests that: "If career and family were made more compatible, through policies like flexible work arrangements and paid parental leave for both men and women, then perhaps women would not worry as much about juggling career and children."

And perhaps men might also realize that they, too, can consider careers that allow them to play a bigger role in family life. With more men than ever lobbying for paternity leave and other flexible options that allow them to play a larger role on the home front, change still may be on its way.

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