Perinatal risk factors for infantile hypertrophic pyloric stenosis: A meta-analysis

Background Infantile hypertrophic pyloric stenosis (IHPS) is the most common surgical cause of nonbilious vomiting in infancy. The etiology of IHPS is not completely understood. Hence, we performed a meta-analysis to investigate the association between perinatal factors and IHPS onset. Methods The MEDLINE, EMBASE, PubMed and Cochrane Library databases were searched for studies published in English before December 2016. The combined odd ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects models. Results Fifteen studies were included. Several perinatal factors, including first-born (OR 1.19, 95% CI: 1.07–1.33), cesarean section delivery (OR 1.63, 95% CI: 1.53–1.73), preterm birth (OR 1.37, 95% CI: 1.12–1.67), and bottle-feed (OR 2.46, 95% CI: 1.76–3.43), were significantly associated with the IHPS onset. Among these, bottle-feed was the most significantly risk factor for IHPS onset. Although few studies have evaluated the relationship between perinatal factors and IHPS, they have major limitations including retrospective collection of data on perinatal events and testing of multiple hypotheses without appropriate statistical corrections. Conclusions First-born, cesarean section delivery, preterm birth, and bottle-feed are associated with the development of IHPS. Well-designed future studies are needed to help understand the etiology of IHPS. Type of study Systematic reviews and meta-analyses. Level of evidence Level III.