Infant colic is often defined by the “rule of threes.” According to this definition, which has been widely used since its publication in the journal Pediatrics in 1954, a colicky baby is one who “otherwise healthy and well fed, [has] paroxysms of irritability, fussing, or crying lasting for a total of 3 hours per day and occurring more than 3 days in any 1 week.” These behaviors, which are unresponsive to attempts at soothing, usually begin during the second to sixth week of life.

Colic can cause anxiety and depression in mothers. And, prolonged periods of inconsolable crying and distress have been implicated as primary provocations of behaviors that can result in shaken baby syndrome , a type of brain damage caused by violent shaking or impact to a baby's head.

Despite the havoc a colicky baby can create in a family, most pediatricians believe the condition is short-lived and has little lasting effect on the mental health of mothers. However, previous studies had shortcomings that prevented definitive support for this view. The study published in the Archives of Pediatric and Adolescent Medicine is a more reliable prospective cohort study that provides strong evidence that most cases of colic do indeed subside by three months without lasting effects on maternal anxiety or depression.

About the Study

Researchers in Canada recruited 547 mother-infant pairs to the study between January 15 and September 16, 1999. The mothers were approached after giving birth, but before being discharged from the hospital.

The mothers filled out a questionnaire approximately one week after being discharged from the hospital and answered questions about infant nutrition, prenatal and postnatal health behaviors, and demographic and biological factors. They also answered questions that allowed the researchers to assess maternal anxiety and depression, and the level of social support they were receiving.

At six weeks and again at three months the mothers filled out similar questionnaires that omitted questions about maternal anxiety, depression, and social support, but added questions about their infants’ crying behaviors.

Finally, at six months after giving birth, the mothers completed a questionnaire that included questions about maternal anxiety and depression.

Using the “rule of threes” definition, the researchers analyzed the questionnaires to determine prevalence of colic at six weeks and three months. They then determined the lasting effects of colic on maternal mental health by assessing the change in anxiety and depression scores between the one-week and six-month questionnaires.

The Findings

Out of 547 infants in this study, 131 infants, or 23.9%, had colic at six weeks. Of these, only 18 infants (13.7%) still had colic at three months. This means that 86.3% of the cases of colic that had been identified at six weeks had remitted by three months.

The researchers also found that infants whose colic had subsided by three months were significantly more likely to be female and their mothers were significantly more likely to have:

  • Received obstetric anesthesia or analgesia during labor and/or delivery
  • Been employed outside the home during pregnancy
  • Consumed alcohol or caffeine during the first three months of their infant’s life

When examining maternal anxiety, the researchers found that although mothers whose infants were colicky at six weeks had a smaller reduction in anxiety and depression scores over six months than mothers whose infants were never colicky, the difference was not statistically significant.

The major limitation of this study was that the researchers were unable to determine what, if any, relief the mothers had from caring for a fussy infant. The mothers described what resources they had access to, but were not specifically questioned about whether they actually used any health care services in response to their infant’s crying or if they actually sought relief when they felt overwhelmed. But because most of the women in this study were married and financially secure, and because the study was done in Canada where the women would have had access to universal healthcare, the assumption is that the mothers had the opportunity to cushion the effects of their children’s colic. In addition, the study started out with 856 mother-child pairs, with response rates decreasing with each subsequent stage of data collection. It is possible that some of the attrition was due to the factors examined in this study.

How Does This Affect You?

This study provides a light at the end of the tunnel for parents caring for infants with colic. Though caring for colicky babies can be tiring and frustrating, parents should keep in mind that in most children, the condition will subside by three months. It is also reassuring to note that maternal anxiety and depression associated with caring for a colicky child does not appear to have lasting effects.

There are no treatments for colic, other than the passage of time. You'll have to try lots of different remedies to care for a colicky infant. What works during one episode of colic may not work the next time. If you feel yourself getting frustrated or angry, put the baby down in the crib until those feelings have passed and do not hesitate to get help.