A nationwide survey of incidence rates and risk factors of inguinal hernia in preterm children

Abstract

Purpose: Clinical observations showed a higher incidence rate of inguinal hernia (IH) in preterm infants. In this study, we calculated the incidence rate of preterm IH from the National Health Insurance Research Database (NHIRD) of Taiwan. Methods: From NHIRD, 92,308 subjects born in the year of 1997–2005 were randomly selected as the study cohort. The medical claims of these subjects from birth to 6th year of age were analyzed. Preterm births were defined using ICD code 765.1*. Risk factors such as birth weight, lung disorders, and ventilator supports before IH repairs were investigated. The risk of incarceration and bowel resection were also evaluated. Results: From 92,308 subjects, 2560 preterm births were identified. IH was repaired in 231 preterm (9.02%) and 3650 term subjects (4.07%). Male (preterm 13.3% and non-preterm 6.3%) had more hernia repairs than female (preterm 3.8% and non-preterm 1.6%). The incidence rate of IH is 13.7% for those under 1500 g, 8.2% for those 1500–1999 g, 7.7% for those 2000–2499 g, and 6.3% for those above 2500 g. The incidence rate of IH in preterms with past history of lung disorders and ventilation supports is 8.7 and 13.6%, respectively. There was no significant difference in the incidences of incarceration and bowel resection between preterms and non-preterms. Conclusions: Birth weight under 2500 g is a significant risk factor for IH repairs. Other risk factors are male gender, past history of lung diseases, and ventilator supports.