Domestic violence could affect children even before they are born, according to a recent study.

Researchers from Michigan State University have linked the abuse of pregnant women and emotional and behavioral trauma symptoms in their children within the first year of life. Symptoms include nightmares, startling easily, being bothered by loud noises and bright lights, avoiding physical contact and having trouble experiencing enjoyment.  

"For clinicians and mothers, knowing that the prenatal experience of their domestic violence can directly harm their babies may be a powerful motivator to help moms get out of these abusive situations," Alytia Levendosky, co-author of the study, said in a statement.

For the study, researchers collected data from nearly 200 mothers between the ages of 18 and 34. The researchers examined the women's parenting styles and also took into account risk factors such as drug use and other negative life events, marital status, age and income.

Researchers found a surprisingly strong relationship between am mother's prenatal abuse by a male partner and postnatal trauma symptoms in her child.

Prenatal abuse could cause changes in the mother's stress response systems, increasing her levels of the hormone cortisol, which in turn could increase cortisol levels in the fetus.

Levendosky said many domestic violence survivors who didn't believe the abuse would affect their child until the child was old enough to understand what was going on.

"They might say things like, 'Oh, I have to leave my partner when my baby gets to be so-and-so age --you know, 3 or 4 years old -- but until then, you know, it's not really affecting him, he won't really remember it,'" she said. "But I think these findings send a strong message that the violence is affecting the baby even before the baby is born."

The findings are detailed in the research journal Child Abuse & Neglect.