It's a question lots of new mothers ask: "Should I let my baby cry it out?" The subject has been debated by parents and psychologists for at least half a century. "Cry it out" is an approach parents use to get babies to sleep on their own that entails letting them cry themselves to sleep. Some parents and experts argue that it is harmful and that immediately responding to a crying infant enhances the infant-mother attachment. Proponents hold that permitting infants to cry reduces the duration of crying and teaches babies to self-soothe.

Now a new study provides some support for the cry-it-out approach. Researchers assessed the sleep training practices of 178 infants and their caregivers and found that crying it out had no negative impact on infant-mother attachment and noted a possible reduction in crying duration and frequency.

The infants and their caregivers were assessed at birth and at three, six, and 18 months of age. Mothers reported at each assessment point whether they let their infant cry it out, with answers categorized as "no cry-it-out," "a few times," and "often." They reported on the duration of their infant's crying during the morning, afternoon, evening, and overnight and the frequency of the crying at birth, and at three and 18 months. Lastly, the researchers assessed attachment type and infant behavior at 18 months.

Most parents in the study never left their infant to cry it out immediately after birth; more left their infant to cry it out "a few times" or "often" as time passed. Leaving an infant to cry at birth was associated with reduced crying duration at 18 months and reduced crying frequency at three months. Leaving an infant to cry at three months was associated with reduced crying duration at 18 months. The strength of these associations, however, was statistically weak.

There were no associations between leaving the infant to cry at any time and subsequent attachment and behavioral development at 18 months. The authors advised parents to make decisions they are comfortable with regarding crying it out. They acknowledged that it might be difficult or stressful for parents to respond immediately to every cry but emphasized that in the context of a warm infant-mother relationship, letting an infant cry it out is not harmful.-Joan Zolot, PA