Worldwide prevalence of colic ranges from 17% to 25% in the first 6 weeks of life, dropping to 11% by 8-9 weeks, and to only 0.6% by 10-12 weeks.[2]Wolke D, Bilgin A, Samara M. Systematic review and meta-analysis: fussing and crying durations and prevalence of colic in infants. J Pediatr. 2017 Jun;185:55-61.e4.
https://www.jpeds.com/article/S0022-3476(17)30218-4/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/28385295?tool=bestpractice.com
Prevalence rates in prospective European studies range from 3% to 28%, and in retrospective studies from 8% to 40%.[3]Canivet C, Hagander B, Jakobsson I, et al. Infantile colic - less common than previously estimated? Acta Paediatr. 1996 Apr;85(4):454-8.
http://www.ncbi.nlm.nih.gov/pubmed/8740304?tool=bestpractice.com
[4]Crowcroft NS, Strachan DP. The social origins of infantile colic: questionnaire study covering 76,747 infants. BMJ. 1997 May 3;314(7090):1325-8.
http://www.ncbi.nlm.nih.gov/pubmed/9158470?tool=bestpractice.com
[5]Hogdall CK, Vestermark V, Birch M, et al. The significance of pregnancy, delivery and postpartum factors for the development of infantile colic. J Perinat Med. 1991;19(4):251-7.
http://www.ncbi.nlm.nih.gov/pubmed/1960629?tool=bestpractice.com
The prevalence rate in the Asian population is considerably lower.[6]Lee K. The crying pattern of Korean infants and related factors. Dev Med Child Neurol. 1994 Jul;36(7):601-7.
http://www.ncbi.nlm.nih.gov/pubmed/8034122?tool=bestpractice.com
The wide variation in the prevalence rate may be explained by the differences in study design, method of data collection, site of recruitment, ethnic differences, and definition of infantile colic. Prospective studies are more reliable, as retrospective studies are prone to recall bias.
Colic occurs equally in both male and female infants.[7]Lucassen PL, Assendelft WJ, van Eijk JT, et al. Systematic review of the occurrence of infantile colic in the community. Arch Dis Child. 2001 May;84(5):398-403.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1718751/pdf/v084p00398.pdf
http://www.ncbi.nlm.nih.gov/pubmed/11316682?tool=bestpractice.com
Infants with colic tend to have siblings who also have this condition. While some investigators have reported an increased incidence in first-born infants, others have not found such an association.[4]Crowcroft NS, Strachan DP. The social origins of infantile colic: questionnaire study covering 76,747 infants. BMJ. 1997 May 3;314(7090):1325-8.
http://www.ncbi.nlm.nih.gov/pubmed/9158470?tool=bestpractice.com
[8]St. James-Roberts I, Halil T. Infant crying patterns in the first year: normative community and clinical findings. J Child Psychol Psychiatry. 1991 Sep;32(6):951-68.
http://www.ncbi.nlm.nih.gov/pubmed/1744198?tool=bestpractice.com
Some investigators have found that infantile colic is more common in low birth weight infants, but this is not a consistent finding.[4]Crowcroft NS, Strachan DP. The social origins of infantile colic: questionnaire study covering 76,747 infants. BMJ. 1997 May 3;314(7090):1325-8.
http://www.ncbi.nlm.nih.gov/pubmed/9158470?tool=bestpractice.com
[9]Sondergaard C, Skajaa E, Henriksen TB. Fetal growth and infantile colic. Arch Dis Child Fetal Neonatal Ed. 2000 Jul;83(1):F44-7.
http://www.ncbi.nlm.nih.gov/pubmed/10873171?tool=bestpractice.com
In one large cohort, infants who were small for their gestational age (birth weight below 10th percentile) were at increased odds of infantile colic across all gestational age groups.[10]Milidou I, Søndergaard C, Jensen MS, et al. Gestational age, small for gestational age, and infantile colic. Paediatr Perinat Epidemiol. 2014 Mar;28(2):138-45.
http://www.ncbi.nlm.nih.gov/pubmed/24261325?tool=bestpractice.com