Effect of informed parental consent on mothers' knowledge of newborn screening.

To determine whether knowledge was improved as a result of obtaining informed consent from parents for newborn screening of their infants for phenylketonuria (PKU) and other hereditary metabolic disorders, new mothers in seven Maryland hospitals were interviewed either before receiving a standard disclosure (n = 210) or after giving consent (n = 418). The mean knowledge score of the women interviewed after giving consent was significantly higher (P less than .001). Receiving the disclosure was a more powerful predictor of knowledge score, accounting for 40% of the variance, than demographic factors, which accounted for 9%. Women whose consent was obtained just prior to discharge tended to have lower knowledge scores than women whose consent was obtained earlier (P = .03). Women with higher knowledge scores were somewhat less likely to favor consent than women with lower scores. Although consent may not be appropriate for some low-risk procedures, informing parents can be easily and inexpensively accomplished.