Why are they having infant colic? A nested case-control study.

We aimed to analyse infant (birth characteristics, feeding type, faecal enzyme activities) and environmental (maternal smoking, nutrition and psychological status, mother-child bonding, family structure, support for the mother, familial atopy) risk factors for infant colic and to follow infants with respect to physical growth, sleeping status up to 8 months of age in a nested case-control study. 660 mothers who delivered at Dr Zekai Tahir Burak Maternity Hospital, were enrolled within 3-72 h post delivery. Each infant with inconsolable persistent crying and four matched infants with no crying episodes were invited by phone to Hacettepe University Ihsan Doğramacı Children's Hospital at 30-45 days post partum. At 40-55 days, we examined the infants and gave mothers a questionnaire, including crying characteristics of the infants; 47 infants were diagnosed with colic and 142 as non-colic. When the infants were 7-8 months old, another interview was done. The colic group had higher proportions of less-educated (≤ 8 years) and smoking mothers, extended family and families with domestic violence than the non-colic group. The colic group of mothers had significantly higher rates of 'impaired bonding' in the Postpartum Bonding Questionnaire, higher scores on the Edinburgh Postnatal Depression Scale, higher scores for hostility subscales of the Brief Symptom Inventory and a more irregular sleep pattern than the non-colic group. No differences were revealed for faecal enzyme activities. At 7-8 months, the colic group was shorter than the non-colic group. Colic was associated with various perinatal factors (maternal education, smoking habits, cheese consumption, hostility scores and domestic violence) and having colic in infancy negatively affected the sleeping pattern and the height of the infant.