First-time parents make mistakes -- and that's understandable, because most people have limited exposure to newborns until they have one themselves. Sure, you may have done some babysitting, but that hardly prepares you for being fully responsible for a tiny person's life.

Many of the tasks involved -- like feedings, diaper changing, and getting them to sleep -- rapidly get easier as you gain experience. And once you have them figured out, you can (mostly) stop stressing about them.

But some mistakes that first-time parents can make will have a longer-lasting impacts, and the ones that involve our financial choices often fall into that category.

With Mother's Day just around the corner, MassMutual has released the results of a survey about the financial habits and regrets of moms with children under the age of 5. Among its respondents, 67% said they had not started a college fund for their child yet -- and that was one of their biggest money-and-kids-related regrets. But it wasn't the No. 1 answer.

A woman holds a newborn baby.

Babies, as they say, do not come with instruction manuals. Image source: Getty Images.

Did I really need to buy that?

It's easy to relax your financial vigilance right after you have a child because there are just so many other things to worry about. Starting a college fund or crafting a budget can take a back seat to day-to-day and hour-to-hour concerns. Among the moms surveyed, however, one item was the clear leader when it came to their top financial regrets: overspending on nonessential baby and kid items (clothes, gadgets, and toys).

That was named by 40% of those surveyed, far more than the 16% who most regretted continuing to spend money on themselves. The only other issue common to more than 5% respondents was a failure to save enough for college, which was named by 15%. Interestingly, 25% of those surveyed said they had no regrets in this arena at all

"No regrets, only learnings," said Mass Mutual Head of Brand and Advertising Jennifer Halloran in a statement emailed to The Motley Fool. "One common thread in my personal and professional experiences has led to this simple yet potentially life-changing advice: control what you can control. The hardest step is the first step."

Halloran, a mother of five herself, recommends evaluating all of one's financial options, then making a decision. That's the approach she has followed.

"Be selective with the choices you make and how you invest your -- and your child(ren)'s -- time and family's hard-earned money," she said. "Opportunities that provide life experiences and lessons for your child(ren) can be prioritized in the mix of options. For example, as a mom of five, I've witnessed the lifelong lessons that sports have provided to my own children as they navigate through each chapter in their lives."

Take a long-term approach

The challenge that both moms and dads face is that they have to simultaneously address both the short and long terms when making decisions for themselves and their children. Are piano lessons for your 8-year-old today more important than saving for college tuition that's a decade away from coming due? In Halloran's view, it's important to properly weigh the longer horizon.

"Many women are focused on successfully managing their household and family activities, plus community and other commitments, on a daily basis. Women need to seize the opportunity to change what they do today to impact future years, too," she said.

It's also important to remember that there are no one-size-fits-all-families answers. As a parent, it may make sense to deny your child something today so that you can save more for his or her future. That may mean college tuition, seed money to start a business, or who knows what --- because no matter how much you think you know, children have a way of confounding our expectations.