Oxytocin, more commonly called the "love hormone," is a potent, natural-occurring chemical believed to have a wide variety of physical and psychological effects. Now, a new study presented at the Society for Personality and Social Psychology annual meeting in San Diego links a woman's oxytocin levels to the chances she'll get divorced shortly after giving birth.

For the study, the research team collected saliva samples from 341 pregnant women during their first trimester of pregnancy, as well as their third trimester and again seven to nine weeks after they gave birth. Two and a half years later, researchers followed up with 188 of the mothers to see how their marriages were doing. Approximately 90 percent of the women were still married to their original partners, while seven women had gotten separated

Researchers found when women had lower oxytocin levels during their first trimester and weeks after giving birth, they were more likely to get divorced within the first few years of their child’s life. On the other hand, for every unit increase in oxytocin during the first trimester, the odds of their marriage surviving increased by roughly seven times. Each unit increase of oxytocin after they gave birth increased those odds by nearly nine times.

"What these data suggest is that lower maternal oxytocin levels associated with the risk of relationship dissolution by the time the child is a toddler," the study’s co-author Jennifer Bartz, a psychologist at McGill University in Canada, told an audience at the meeting.

According to the American Psychological Association, oxytocin plays an intrinsic role in maternal bonding, lactation, social bonding, sexual pleasure, and potentially marital bonds. Researchers first discovered oxytocin is released into the mother’s blood after she gives birth and during breastfeeding in order to bond the mother to their newborn. Now, in light of the new research, it seems the higher the levels remain after giving birth, the more likely a bonding ripple effect will occur throughout the household, Bartz concluded.

"There are lots of good reasons why it doesn't make sense to stay in a relationship," Bartz said. "Just because we've identified a characteristic in the mother doesn't mean it's causal."

Bartz and her research team plan on studying more couples in order to test how marriage quality plays a role in the likelihood of divorce. The results are still preliminary, Bartz said, but exploring further "would probably give us a lot of insight."

Source: Bartz J, et al. Society for Personality and Social Psychology annual meeting. 2016.