If you're a new mom who constantly hovers over your baby to make sure he or she is still breathing, or sterilizes the same bottles time and again, research suggests you're not alone.

In the weeks after giving birth, 11 percent of mothers said they were experiencing obsessive-compulsive symptoms, a new study in The Journal of Reproductive Medicine found. And six months after giving birth, about half still had symptoms, while another 5 percent who had no symptoms initially, developed them.

"One of the questions this raises is, does this represent true pathology? Is this a disease in need of treatment, or are these very common thoughts somehow adaptive and appropriate to a new mother?" study author Dr. Dana Gossett, chief and assistant professor of obstetrics and gynecology at Northwestern University Feinberg School of Medicine, told The Huffington Post. "Where that line falls, we don't really know."

Symptoms of obsessive compulsive disorder (OCD) include both obsessions, which are unwanted, persistent thoughts or images, as well as compulsions -- repetitive behaviors a person feels driven to perform in response to their obsessions. Because the new study relied on women answering questions about what they were feeling, it showed only whether they had those symptoms, not if they met diagnostic criteria for OCD. Results were taken from 461 women who delivered babies in 2009 and completed mental health surveys two weeks after birth. Some 329 also answered questions after six months.

Overall, the prevalence of obsessive compulsive symptoms was much higher in the new moms than in the general population, where it is about 2 to 3 percent. The biggest obsession was with dirt or germs, followed by women constantly checking to ensure they did not make a mistake.

Gossett said she and her colleagues focused on new moms rather than moms and dads because women regularly cite childbirth as a trigger of the disorder. Though the cause of OCD isn't fully understood, it is thought to be stress-responsive.

"Part of it may simply be that it's a stressful life event, but there may be specific hormonal components that are unique to women," Gossett said.

A separate study published this week in the journal Pediatrics found that up to 17 percent of new moms may experience postpartum anxiety during the initial hospital stay, an acute phenomenon it linked to lower breastfeeding rates. The authors of that paper said that screening women while they're in the hospital for anxiety specifically could help improve those outcomes.

Experts caution there is a fine line between making sure women get help when they need it and medicalizing normal behaviors. It is not clear whether the symptoms experienced by women in the study would eventually resolve on their own or turn into lifelong OCD.

"Most mothers are going to experience some degree of increased worry and vulnerability because of the profound experience of being responsible for another creature for the first time," said Dr. Samantha Meltzer-Brody, director of the Perinatal Psychiatry Program, UNC Center for Women's Mood Disorders at the University of North Carolina at Chapel Hill, who did not work on the new study. "It's normal to a certain extent, until it interferes with functioning."

She said worrying about germs and dirt can be perfectly normal, but spending hours a day wiping and sterilizing may not be. Likewise, some fears about dropping your baby may be expected, but if new moms find they can't bring themselves to walk downstairs because they're so terrified, that is far more serious.

"If you are having ruminating thoughts," Meltzer-Brody said, "Ask yourself this simple question: 'Is this interfering with or changing my behavior in a way that I'm not happy about?'"

CORRECTION: This post previously misidentified Meltzer-Brody's title and affiliation.