A new study may have unlocked the mystery behind being a good parent and having a good sex life.

Couple's feet under covers in bed
Credit: Shutterstock.com

It happens to the best of us: You and your partner are getting along swimmingly, decide to have a baby—and then all hell breaks loose. After your little love bug arrives, your once-romantic nights and weekends become an endless stretch of crying jagsdiaper changes, and round-the-clock feedings. And let's not even talk about the inevitable bickering that comes when you're both running on roughly 90 minutes of sleep.

Is it any wonder our relationship takes a hit when baby makes three?

But science may have uncovered the secret to sustaining your bond even though your shoulders are covered in spit-up: Share the parenting duties. (#bestsolutionever) According to new research, when both parents equally split the childcare workload, they tend to think positively about their relationship—and their sex life. This applies to couples across the board, whether they're married or not.

These findings, based on a survey of 500 heterosexual partners, reflect the egalitarian attitude among today's moms and dads. We're not just okay divvying up responsibilities—we prefer it. "The main story here is that this study clearly shows that when it comes to child care, when couples share the workload and both partners pitch in, it produces higher quality solid relationships, less conflict, better communication and more intimacy," says Daniel Carlson, the study's author and an assistant professor of sociology at Georgia State University.

In the survey, parents assessed how childcare was divided in their home. (Childcare was defined here as making and enforcing rules, disciplining, supervising, offering praise, and playing with your child.) They also graded their relationship based on level of satisfaction, how much conflict they encountered, and their sex life.

The results were fascinating: When mom takes on the majority of the baby's care, both partners tend to give their sex life low marks. The picture changes a bit when dad is the primary caregiver. There, both partners tend to look just as kindly on the health of their relationship and sex life as couples who go in 50-50. In fact, moms rank the quality of their sex life even higher than moms who split duties equally. Dads, meanwhile, give the quality of their sex life low marks.

It all boils down to the level of satisfaction with the childcare arrangement you and your partner have struck. Content couples tend to have less conflict and feel better about their relationship. "We don't really know exactly what is behind this," Carlson explains. "But it could be that a relationship suffers when one person feels overburdened, overworked or overtired. Or it could be that a certain degree of dissatisfaction with having to do all the work, while the other isn't doing any of it, undermines the bond between couples. And that can carry over to the bedroom."

This makes perfect sense. If you're the default parent—and not by choice —it's all too easy to resent a seemingly footloose and fancy-free partner who's not wearing a day-old shirt covered in baby drool stains. No matter what your child's age, parenting is a major undertaking, and it helps if you and your partner are in the thick of it together. That shared connection doesn't just help carry you both through bouts of colic, it also helps bring the heat back into the bedroom. And it's way cheaper than date night.

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Bonnie Gibbs Vengrow is a New York City-based writer and editor who traded in her Blackberry and Metro card for playdates and PB&J sandwiches—and the once-in-a-lifetime chance to watch her feisty, funny son grow up. Follow her on TwitterPinterest, and Google+.