The stress of being a new parent can kill a couple's sex life, a new study revealed

Both parents experience an enormous amount of stress after the birth of their first child - adapting to being a caregiver for the first time, in addition to surviving on very little sleep.

However, first-time mothers often experience even higher levels of stress than new fathers, according to scientists from Penn State University. That's because a new mom often bears most of the responsibility of caring for the infant, while struggling to meet social pressures to be the "perfect mother."

And now, a new study revealed that the stress a mother endures as a new parent actually funnels into her sex life - and negatively affects the sexual satisfaction of both parents.

The team of Penn State researchers analyzed data from 169 expectant heterosexual couples, who were asked about the parenting stress they were experiencing in the six months after the baby was born. Twelve months after the baby's birth, the parents then reported on their overall sexual satisfaction.

Published in the journal Sex Roles, the study found that mothers reported greater sexual satisfaction at 12 months than the fathers did. Furthermore, 69% of the women reported being "somewhat to very satisfied" with their sex lives, while only 55% of men reported being "somewhat to very satisfied."

"Interestingly, we found that men's parenting stress had no impact on either men's or women's sexual satisfaction," study author Chelon E. Leavitt, a PhD candidate, said in a statement.

Yet, the parenting stress that women felt was found to affect the sexual satisfaction of both partners.

"When new moms feel fatigued by the added responsibilities of parenting, they may feel less sexual," Leavitt said. "The sexual relationship is interdependent, so when a mom feels greater stress due to parenting, not only is her sexual satisfaction diminished, the dad's sexual satisfaction is also affected."