title: Prevalence and natural course of gastroesophageal reflux symptoms: a 1-year cohort study in Thai infants.
abstract: BACKGROUND
  Epidemiologic studies in adults suggest that the nature of gastroesophageal reflux may differ among various ethnic groups. Until recently, there has been limited information concerning the epidemiology of gastroesophageal reflux in non-Western children. The objectives of this cohort study were to investigate the prevalence of symptoms related to gastroesophageal reflux in Thai infants and to describe the clinical course of reflux regurgitation during the first year of life.
  
  
  METHODS
  A cohort study was performed in 216 healthy neonates who attended the well-baby clinic of Songklanagarind Hospital between March and June 1998. All neonates were followed up, at regular well-baby clinic visits, for 1 year for reflux symptoms and clinical progress. Information concerning gastroesophageal reflux symptoms was obtained by interviewing the parents and from their diary records. An infant who regurgitated at least 1 day per week was considered to have reflux regurgitation.
  
  
  RESULTS
  No infant with clinical features of pathologic gastroesophageal reflux or other reflux symptoms apart from regurgitation were seen during this study period. Of 145 infants in a 1-year cohort, the prevalence of reflux regurgitation peaked at 2 months at 86.9% and significantly decreased to 69.7% at 4 months, 45.5% at 6 months, and 22.8% at 8 months. At 1 year of age, only 7.6% of infants still had reflux regurgitation. Most Thai infants with gastroesophageal reflux had mild symptoms: 90% of them regurgitated only one to three times per day, and daily regurgitation was reported in a low percentage. Comparing infants with reflux regurgitation and those without, the standard deviation scores of body weight for age were similar. There was no significant difference in prevalence of reflux regurgitation between breast-fed and bottle-fed infants.
  
  
  CONCLUSIONS
  The nature of gastroesophageal reflux in Thai infants differs from that in Western infants. The prevalence of reflux regurgitation in Thai infants was very high at 1 to 2 months of age; however, many infants became symptom-free by 6 months. The type of feeding (breast milk vs. bottle milk) had no influence on the prevalence of reflux regurgitation.
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Songkla, Thailand. oseksit@ratree.psu.ac.th
authors.forename: Seksit
authors.initials: S
authors.lastname: Osatakul
authors.forename: Hutcha
authors.initials: H
authors.lastname: Sriplung
authors.forename: Areeruk
authors.initials: A
authors.lastname: Puetpaiboon
authors.forename: Cha-on
authors.initials: CO
authors.lastname: Junjana
authors.forename: Suthaporn
authors.initials: S
authors.lastname: Chamnongpakdi
mesh_terms: D000367:Age Factors; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005764:Gastroesophageal Reflux / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D007225:Infant Food; D007231:Infant, Newborn; D008297:Male; D008895:Milk, Human / Q000378:metabolism*; D015995:Prevalence; D013785:Thailand / Q000453:epidemiology