“Hypertrophic pyloric stenosis in infants following pertussis prophylaxis with erythromycin.”
According to this study published in 1999 from the Centre for Disease Control and Prevention in Atlanta Georgia, infants who are given the antibiotic erythromycin have an increased chance of developing infantile hypertrophic pyloric stenosis, compared with infants who do not take antibiotics.
The study involved 157 babies who were all less than 3 weeks of age and were treated with erythromycin after being exposed to whooping cough.
A total of 5% of the newborns that took erythromycin developed hypertrophic pyloric stenosis, which was treated with surgery.
This figure is markedly higher than the average incidence of the disorder which is only 0.1% to 0.3%.
Knoxville, Tennessee, 1999. MMWR 1999; 48 (49):1117-21.