Estimated patient numbers per centre during a 1-month study period are: 1-2 gastroschisis, 1-2 anorectal malformations, 11 appendicitis, 14 inguinal hernias, 1 intussusception (29 patients per centre). We aim to include a minimum of 50 centres, which would generate 1450 patients. Estimates were calculated using the mean number of patients presenting per month to all institutions from SSA who have published data on these conditions.