Gastroesophageal reflux disease in infants: how much is predictable with questionnaires, pH-metry, endoscopy and histology?

Symptoms of gastroesophageal reflux disease (GERD) are common in infants. It is often difficult to discriminate between physiological and pathologic gastroesophageal reflux, although this discrimination is essential to determine which infants to evaluate and treat. Objectives: To identify the prevalence of reflux symptoms in infants and to evaluate the predictive value of a questionnaire and the correlation between pH study, histology and clinical score. Methods: Parents of 100 unselected infants visiting the well-baby clinic and 100 infants suspected of having gastroesophageal reflux disease were asked to fill in a 35-item questionnaire. A validated score, the Orenstein I-GERQ, was applied for selected questions. All infants suspected of having gastroesophageal reflux disease underwent prolonged esophageal pH monitoring and 44 or 100 underwent upper gastrointestinal tract endoscopy with esophageal biopsy. Results: Parents of infants with suspected gastroesophageal reflux disease reported significantly more regurgitation (68% versus 45%, P < 0.05) and crying (51% versus 20%, P < 0.01) compared with the parents of healthy infants. A pathologic pH study (reflux index > 10%) was found in 21 of 100 (21%) infants and was significantly associated only with pneumonia, apnea with fussing (P = 0.013 for both), defecation less than once a day (P = 0.033) and constipation (P = 0.05). Esophagitis was present in 17 of 44 (39%) and no one question was found to be significantly predictive. 38% of infants with a pathologic pH study had a normal esophageal biopsy and 53% of infants with histologic esophagitis had a normal pH study. Discordance between pH study and biopsies occurred in 14 of 44 (32%) patients. The Orenstein I-GERQ cut-off score failed to identify eight of 31 (26%) infants with gastroesophageal reflux disease. Conversely, the score was positive in 17 of 22 (81%) infants with normal biopsy and pH study and in 14 of 47 (30%) infants with normal pH study. Conclusions: Clinical symptoms, histology and pH study show poor correlation in infants. Clinical symptoms such as regurgitation and crying are less frequent in unselected infants than in infants suspected of gastroesophageal reflux disease. However, questionnaires are poorly predictive for the severity of gastroesophageal reflux disease, as they do not correlate with esophageal acid exposure as measured by pH-metry and with esophagitis as evaluated by histology of esophageal biopsies.