Early-onset infantile hypertrophic pyloric stenosis: a case report

Infantile hypertrophic pyloric stenosis (IHPS) is a common cause of non-bilious projectile vomiting in infants, typically presenting between 4 and 8 weeks of age. Early-onset cases, particularly those occurring within the first few days of life, are rare and often challenging to diagnose due to lack of standardized sonographic criteria for this age group. A 12-day-old male neonate presented with persistent non-bilious projectile vomiting beginning on the first days of life. He was born at full term via spontaneous vaginal delivery to a 26-year-old primigravida mother after an uncomplicated pregnancy. Initial evaluation at a local health center led to conservative management for presumed gastroesophageal reflux. Persisting symptoms prompted referral after an initial ultrasound showed a pyloric muscle thickness of 3.6 mm and a length of 16 mm, suggestive of IHPS. However, due to the uncommon occurrence of IHPS at such an early age, a repeat ultrasound was done, which was interpreted as normal. An upper gastrointestinal contrast study was done to rule out intestinal malrotation and other sources of gastric outlet obstruction. Due to the persistence of symptoms, a third ultrasound was done on day of life 21, which showed a pyloric length of 16.6 mm and a thickness of 4.2 mm, conclusive for IHPS. The patient underwent an open Ramstedt pyloromyotomy without complications. The postoperative recovery was complicated by a hospital-acquired pneumonia, which was successfully treated. The patient was discharged on postoperative day 16 and remained asymptomatic at six months of follow-up, with normal growth and development. Pyloric stenosis rarely occurs within the first few weeks of life but should be included in the differential diagnosis of newborns who develop persistent projectile non-bilious vomiting.