Which intervention should the nurse implement for an infant with a myelomeningocele awaiting surgical correction?

Placing the infant in the prone position is the best intervention for a newborn with a myelomeningocele awaiting surgical correction. This positioning helps to minimize pressure on the exposed spinal cord and surrounding tissues, reducing the risk of damage or injury to the neural structures. By lying the infant on their stomach, the defect is less likely to be traumatized or contaminated, which is particularly important before a surgical intervention is performed.

Upon considering the context of the other options, using disposable diapers may not provide the best protection, as there could be a risk of added pressure on the defect. Performing neurologic checks above the site of the lesion is important for monitoring function, but it does not directly address the immediate care needs of the infant. Washing the area below the defect with a nontoxic antiseptic could present risks if it disturbs the defect or does not provide adequate protection. The priority is to ensure that the defect is protected by keeping the infant prone and reducing the chances of complications before surgery.