Changes

Male circumcision is the most common neonatal surgical procedure. It causes intense pain and measurable changes in behaviour that last up to 1 day. We found that circumcision status was associated with increased infant pain response to routine vaccination at 4-6 months. Circumcised boys had significantly longer crying bouts and higher pain scores. That both outcome measures, pain index, and cry duration, were influenced by circumcision lends credibility to our observations. During the second (HIB) vaccination, circumcision status was more clearly associated with the observed pain response than after DPT. The DPT injection might have had a priming effect in circumcised infants which led them to exhibit even more pain after the HIB injection. The effects of memory and reinforcement on later nocioceptive experience in neonates are not known. Because memory of pain is believed to be important in subsequent pain perception, and the main structures for memory are functional in the neonatal period, it is conceivable that pain from circumcision may have long-lasting effects on pain response and/or perception.<ref name="taddio1995">{{Taddio TaddioA etal 1995}}</ref>